{"id":"CVE-2026-59980","aliases":["DEBIAN-CVE-2026-59980","EUVD-2026-85712","GHSA-8v8h-hg4w-mvq2","MGASA-2026-0349","OESA-2026-4239","OESA-2026-4240","OESA-2026-4241","OESA-2026-4242","PYSEC-2026-4053","SUSE-SU-2026:24216-1","SUSE-SU-2026:4593-1","SUSE-SU-2026:4832-1","UBUNTU-CVE-2026-59980","openSUSE-SU-2026:11556-1","openSUSE-SU-2026:22070-1"],"status":"published","title":"hpack: Unbounded variable integer decoding can cause run-away computation on malformed input","description":"hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","severity":{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00302,"percentile":0.23125,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-400"],"published":"2026-08-19T00:00:00Z","modified":"2026-10-28T02:31:00Z","fixes":[{"ecosystem":"PyPI","package":"hpack","fixed_in":["4.2.0"],"sources":["ghsa","osv"]},{"ecosystem":"Mageia:10","package":"python-hpack","fixed_in":["4.2.0-1.mga10"],"sources":["osv"]},{"ecosystem":"openEuler:22.03-LTS-SP4","package":"python-hpack","fixed_in":["4.0.0-2.oe2203sp4"],"sources":["osv"]},{"ecosystem":"openEuler:24.03-LTS-SP1","package":"python-hpack","fixed_in":["4.0.0-3.oe2403sp1"],"sources":["osv"]},{"ecosystem":"openEuler:24.03-LTS-SP3","package":"python-hpack","fixed_in":["4.0.0-3.oe2403sp3"],"sources":["osv"]},{"ecosystem":"openEuler:24.03-LTS-SP4","package":"python-hpack","fixed_in":["4.0.0-3.oe2403sp4"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Server 16.0","package":"python-hpack","fixed_in":["4.1.0-160000.3.1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Server for SAP applications 16.0","package":"python-hpack","fixed_in":["4.1.0-160000.3.1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Module for Server Applications 15 SP7","package":"python-hpack","fixed_in":["3.0.0-150200.3.5.1"],"sources":["osv"]},{"ecosystem":"SUSE:Linux Enterprise Module for Python 3 15 SP7","package":"python-hpack","fixed_in":["4.0.0-150400.8.6.1"],"sources":["osv"]},{"ecosystem":"openSUSE:Leap 16.0","package":"python-hpack","fixed_in":["4.1.0-160000.3.1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"4.1.0"},{"fixed":"4.2.0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-2","4.0.0-3","4.0.0-4"]},{"source":"osv","ecosystem":"Debian:13","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-3","4.0.0-4"]},{"source":"osv","ecosystem":"Debian:14","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-3","4.0.0-4"]},{"source":"osv","ecosystem":"PyPI","package":"hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.0"}]}],"versions":["1.0.0","1.0.1","1.1.0","2.0.0","2.0.1","2.1.0","2.1.1","2.2.0","2.3.0","3.0.0","4.0.0","4.1.0"]},{"source":"osv","ecosystem":"Mageia:10","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.0-1.mga10"}]}]},{"source":"osv","ecosystem":"openEuler:22.03-LTS-SP4","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0-2.oe2203sp4"}]}]},{"source":"osv","ecosystem":"openEuler:24.03-LTS-SP1","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0-3.oe2403sp1"}]}]},{"source":"osv","ecosystem":"openEuler:24.03-LTS-SP3","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0-3.oe2403sp3"}]}]},{"source":"osv","ecosystem":"openEuler:24.03-LTS-SP4","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0-3.oe2403sp4"}]}]},{"source":"osv","ecosystem":"PyPI","package":"hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.0"}]}],"versions":["1.0.0","1.0.1","1.1.0","2.0.0","2.0.1","2.1.0","2.1.1","2.2.0","2.3.0","3.0.0","4.0.0","4.1.0"]},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server 16.0","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.1.0-160000.3.1"}]}]},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Server for SAP applications 16.0","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.1.0-160000.3.1"}]}]},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Module for Server Applications 15 SP7","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"3.0.0-150200.3.5.1"}]}]},{"source":"osv","ecosystem":"SUSE:Linux Enterprise Module for Python 3 15 SP7","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.0.0-150400.8.6.1"}]}]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.1.0-1","2.0.1-1","2.1.0-1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.0-1","3.0.0-2"]},{"source":"osv","ecosystem":"Ubuntu:20.04:LTS","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.0.0-3","3.0.0-4"]},{"source":"osv","ecosystem":"Ubuntu:22.04:LTS","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-2"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-3","4.0.0-4"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["4.0.0-3"]},{"source":"osv","ecosystem":"openSUSE:Tumbleweed","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.2.0-1.1"}]}],"bundled":2},{"source":"osv","ecosystem":"openSUSE:Leap 16.0","package":"python-hpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.1.0-160000.3.1"}]}]}],"products":[{"vendor":"python-hyper","product":"hpack"}],"references":[{"url":"https://github.com/python-hyper/hpack/security/advisories/GHSA-8v8h-hg4w-mvq2","tags":["x_refsource_CONFIRM","advisory","web","report"]},{"url":"https://github.com/python-hyper/hpack/commit/8cfb02c547740e16dbfe7aba77bad84b297cec2c","tags":["x_refsource_MISC","fix","web","report"]},{"url":"https://cs.opensource.google/go/x/net/+/master:http2/hpack/hpack.go;l=468;drc=8e2b117aee74f6b86c207a808b0255de45c0a18a","tags":["x_refsource_MISC","web","report"]},{"url":"https://docs.rs/http2/0.5.19/src/http2/hpack/decoder.rs.html#403","tags":["x_refsource_MISC","web","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-59980","tags":["advisory"]},{"url":"https://github.com/python-hyper/hpack/releases/tag/v4.2.0","tags":["web"]},{"url":"https://github.com/advisories/GHSA-8v8h-hg4w-mvq2","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/59xxx/CVE-2026-59980.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-59980","tags":["advisory"]},{"url":"https://github.com/python-hyper/hpack","tags":["package"]},{"url":"https://advisories.mageia.org/MGASA-2026-0349.html","tags":["advisory"]},{"url":"https://bugs.mageia.org/show_bug.cgi?id=36197","tags":["report"]},{"url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4239","tags":["advisory"]},{"url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4240","tags":["advisory"]},{"url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4241","tags":["advisory"]},{"url":"https://www.openeuler.org/zh/security/security-bulletins/detail/?id=openEuler-SA-2026-4242","tags":["advisory"]},{"url":"https://pypi.org/project/hpack","tags":["package"]},{"url":"https://www.suse.com/support/update/announcement/2026/suse-su-202624216-1/","tags":["advisory"]},{"url":"https://bugzilla.suse.com/1283035","tags":["report"]},{"url":"https://www.suse.com/security/cve/CVE-2026-59980","tags":["web"]},{"url":"https://www.suse.com/support/update/announcement/2026/suse-su-20264593-1/","tags":["advisory"]},{"url":"https://www.suse.com/support/update/announcement/2026/suse-su-20264832-1/","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-59980","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-59980","tags":["report"]},{"url":"","tags":["advisory"]},{"url":"https://www.suse.com/security/cve/CVE-2016-6581","tags":["web"]}],"sources":{"cve":[{"id":"CVE-2026-59980","title":"hpack: Unbounded variable integer decoding can cause run-away computation on malformed input","description":"hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-09-23T22:07:35.095Z","modified":"2026-09-24T13:25:08.9Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:19:58.560602Z"}],"euvd":[{"id":"EUVD-2026-85712","description":"hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-09-23T22:07:35Z","modified":"2026-09-24T13:25:08Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T17:27:59.466335Z"}],"ghsa":[{"id":"GHSA-8v8h-hg4w-mvq2","title":"hpack: Unbounded variable integer decoding can cause run-away computation on malformed input","description":"### Impact\n\nUsers of the python-hyper/hpack library, most commonly used as downstream dependency of the python-hyper/h2 library (an HTTP/2 client and server implementation). Unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input.\n\n### Patches\nA fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation.\n\n### Workarounds\nSanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-09-24T19:43:26Z","modified":"2026-09-24T19:43:27Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:41:21.616682Z"}],"nvd":[{"id":"CVE-2026-59980","description":"hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-09-23T23:17:11.473Z","modified":"2026-09-30T17:32:07.107Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:12:51.036099Z"}],"osv":[{"id":"CVE-2026-59980","title":"hpack: Unbounded variable integer decoding can cause run-away computation on malformed input","description":"hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-09-23T22:07:35.095Z","modified":"2026-10-28T02:31:00.232786942Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:45:12.933503Z"},{"id":"DEBIAN-CVE-2026-59980","description":"hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-09-23T23:17:11.473Z","modified":"2026-10-01T08:47:30.014640107Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium"}],"updated_at":"2026-11-02T15:45:57.932517Z"},{"id":"GHSA-8v8h-hg4w-mvq2","title":"hpack: Unbounded variable integer decoding can cause run-away computation on malformed input","description":"### Impact\n\nUsers of the python-hyper/hpack library, most commonly used as downstream dependency of the python-hyper/h2 library (an HTTP/2 client and server implementation). Unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input.\n\n### Patches\nA fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation.\n\n### Workarounds\nSanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-09-24T19:43:26Z","modified":"2026-10-01T17:55:38.238084125Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:42.78452Z"},{"id":"OESA-2026-4239","title":"python-hpack security update","description":"hpack provides a simple Python interface to the HPACK compression algorithm,used to compress HTTP headers in HTTP/2.Used by some of the most populer HTTP/2 implementations in Python,HPACK offers a great Python interface as well as optional upgrade to optimised C-based compression routines from nghttp2.\r\n\r\nSecurity Fix(es):\n\nhpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.(CVE-2026-59980)","status":"published","published":"2026-10-16T11:58:29Z","modified":"2026-10-16T12:15:16.604249645Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T15:52:47.643553Z"},{"id":"OESA-2026-4240","title":"python-hpack security update","description":"hpack provides a simple Python interface to the HPACK compression algorithm,used to compress HTTP headers in HTTP/2.Used by some of the most populer HTTP/2 implementations in Python,HPACK offers a great Python interface as well as optional upgrade to optimised C-based compression routines from nghttp2.\r\n\r\nSecurity Fix(es):\n\nhpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.(CVE-2026-59980)","status":"published","published":"2026-10-16T11:58:30Z","modified":"2026-10-16T12:15:05.191018324Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T15:52:47.643553Z"},{"id":"OESA-2026-4241","title":"python-hpack security update","description":"hpack provides a simple Python interface to the HPACK compression algorithm,used to compress HTTP headers in HTTP/2.Used by some of the most populer HTTP/2 implementations in Python,HPACK offers a great Python interface as well as optional upgrade to optimised C-based compression routines from nghttp2.\r\n\r\nSecurity Fix(es):\n\nhpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.(CVE-2026-59980)","status":"published","published":"2026-10-16T11:58:31Z","modified":"2026-10-16T12:15:16.617824516Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T15:52:47.643553Z"},{"id":"OESA-2026-4242","title":"python-hpack security update","description":"hpack provides a simple Python interface to the HPACK compression algorithm,used to compress HTTP headers in HTTP/2.Used by some of the most populer HTTP/2 implementations in Python,HPACK offers a great Python interface as well as optional upgrade to optimised C-based compression routines from nghttp2.\r\n\r\nSecurity Fix(es):\n\nhpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.(CVE-2026-59980)","status":"published","published":"2026-10-16T11:58:31Z","modified":"2026-10-16T12:15:04.189697601Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T15:52:47.643553Z"},{"id":"PYSEC-2026-4053","title":"hpack: Unbounded variable integer decoding can cause run-away computation on malformed input","description":"### Impact\n\nUsers of the python-hyper/hpack library, most commonly used as downstream dependency of the python-hyper/h2 library (an HTTP/2 client and server implementation). Unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input.\n\n### Patches\nA fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation.\n\n### Workarounds\nSanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-10-01T16:38:39.106369Z","modified":"2026-10-01T17:45:03.832893385Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T15:52:57.255153Z"},{"id":"UBUNTU-CVE-2026-59980","description":"hpack is an HTTP/2 Header Encoding for Python. Prior to version 4.2.0, unbounded variable integer decoding can cause run-away computation on malformed input leading to O(n^2) runtime, effectively blocking further processing with large enough unsanitized input. A fix is available in python-hyper/hpack v4.2.0 to restricted variable integer decoding to uint32 to prevent run-away computation. As a workaround, sanitize input to hpack decoder for long sequences of `0xFF` values to prevent malicious use.","status":"published","published":"2026-09-23T23:17:00Z","modified":"2026-10-17T12:56:00.350186752Z","cvss":[{"version":"4.0","score":6.3,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:56:41.911783Z"},{"id":"MGASA-2026-0349","title":"Updated python-hpack packages fix a security vulnerability","description":"An issue was found in the python-hyper/hpack library, most commonly used as\na downstream dependency of the python-hyper/h2 library (an HTTP/2 client\nand server implementation). Unbounded variable integer decoding can\ncause run-away computation on malformed input leading to O(n^2) runtime,\neffectively blocking further processing with large enough unsanitized\ninput.\nA fix python-hyper/hpack v4.2.0 restricts variable integer decoding to\nuint32 to prevent run-away computation.\n","status":"published","published":"2026-08-31T19:40:26Z","modified":"2026-09-01T03:15:03.616845841Z","updated_at":"2026-11-02T15:49:43.795591Z"},{"id":"openSUSE-SU-2026:11556-1","title":"python313-hpack-4.2.0-1.1 on GA media","description":"These are all security issues fixed in the python313-hpack-4.2.0-1.1 package on the GA media of openSUSE Tumbleweed.","status":"published","published":"2026-08-19T00:00:00Z","modified":"2026-08-21T09:15:07.689992841Z","updated_at":"2026-11-02T16:58:39.516824Z"},{"id":"openSUSE-SU-2026:22070-1","title":"Security update for python-hpack","description":"This update for python-hpack fixes the following issue:\n\n- CVE-2026-59980: unbounded variable integer decoding can cause run-away computation on malformed input, leading to\n  quadratic runtime (bsc#1283035).\n","status":"published","published":"2026-10-09T11:44:15Z","modified":"2026-10-19T17:23:12.584286361Z","updated_at":"2026-11-02T16:58:42.426393Z"},{"id":"SUSE-SU-2026:24216-1","title":"Security update for python-hpack","description":"This update for python-hpack fixes the following issue:\n\n- CVE-2026-59980: unbounded variable integer decoding can cause run-away computation on malformed input, leading to\n  quadratic runtime (bsc#1283035).\n","status":"published","published":"2026-10-09T11:44:38Z","modified":"2026-10-21T17:23:10.250467446Z","updated_at":"2026-11-02T15:54:04.519245Z"},{"id":"SUSE-SU-2026:4593-1","title":"Security update for python-hpack","description":"This update for python-hpack fixes the following issue:\n\n- CVE-2026-59980: unbounded variable integer decoding can cause run-away computation on malformed input, leading to\n  quadratic runtime (bsc#1283035).\n","status":"published","published":"2026-10-08T14:22:49Z","modified":"2026-10-09T18:15:03.729050231Z","updated_at":"2026-11-02T15:54:05.838224Z"},{"id":"SUSE-SU-2026:4832-1","title":"Security update for python-hpack","description":"This update for python-hpack fixes the following issue:\n\n- CVE-2026-59980: unbounded variable integer decoding can cause run-away computation on malformed input, leading to\n  quadratic runtime (bsc#1283035).\n","status":"published","published":"2026-10-21T12:48:53Z","modified":"2026-10-22T11:45:04.256285133Z","updated_at":"2026-11-02T15:54:05.838224Z"}]}}