{"id":"CVE-2026-79771","aliases":["BELL-CVE-2026-79771","DEBIAN-CVE-2026-79771","EUVD-2026-65529","GHSA-rh9x-7xjc-vwx2","GHSA-v2fc-qm4h-8hqv","UBUNTU-CVE-2026-79771"],"status":"published","title":"Nokogiri before 1.19.3 Memory Leak via XSLT Transform","description":"Nokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","severity":{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/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":0.00423,"percentile":0.36899,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-401"],"published":"2026-05-06T18:27:38Z","modified":"2026-10-28T02:31:13Z","fixes":[{"ecosystem":"RubyGems","package":"nokogiri","fixed_in":["1.19.3"],"sources":["ghsa","osv"]},{"ecosystem":"Alpaquita:stream","package":"ruby-nokogiri","fixed_in":["1.19.4-r0"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"ruby-nokogiri","fixed_in":["1.19.3+dfsg-1"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"RubyGems","package":"nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.19.3"}]}]},{"source":"osv","ecosystem":"Alpaquita:23","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.13.9-r1"}]}]},{"source":"osv","ecosystem":"Alpaquita:25","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.18.8-r0"}]}]},{"source":"osv","ecosystem":"Alpaquita:stream","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"1.13.9-r1"},{"fixed":"1.19.4-r0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.13.10+dfsg-2","1.14.2+dfsg-1","1.14.3+dfsg-1","1.14.3+dfsg-2","1.15.4+dfsg-1","1.16.0+dfsg-1","1.16.0+dfsg-2","1.16.2+dfsg-1","1.16.4+dfsg-1","1.17.2+dfsg-1~exp1","1.18.10+dfsg-1","1.18.10+dfsg-2","1.18.10+dfsg-3","1.18.2+dfsg-1","1.19.1+dfsg-1","1.19.3+dfsg-1","1.19.4+dfsg-1"]},{"source":"osv","ecosystem":"Debian:13","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.18.10+dfsg-1","1.18.10+dfsg-2","1.18.10+dfsg-3","1.18.2+dfsg-1","1.19.1+dfsg-1","1.19.3+dfsg-1","1.19.4+dfsg-1"]},{"source":"osv","ecosystem":"Debian:14","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.19.3+dfsg-1"}]}],"versions":["1.18.10+dfsg-1","1.18.10+dfsg-2","1.18.10+dfsg-3","1.18.2+dfsg-1","1.19.1+dfsg-1"]},{"source":"osv","ecosystem":"RubyGems","package":"nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"1.19.3"}]}],"versions":["1.0.0","1.0.1","1.0.2","1.0.3","1.0.4","1.0.5","1.0.6","1.0.7","1.1.0","1.1.1","1.10.0","1.10.0.rc1","1.10.1","1.10.10","1.10.2","1.10.3","1.10.4","1.10.5","1.10.6","1.10.7","1.10.8","1.10.9","1.11.0","1.11.0.rc1","1.11.0.rc2","1.11.0.rc3","1.11.0.rc4","1.11.1","1.11.2","1.11.3","1.11.4","1.11.5","1.11.6","1.11.7","1.12.0","1.12.0.rc1","1.12.1","1.12.2","1.12.3","1.12.4","1.12.5","1.13.0","1.13.1","1.13.10","1.13.2","1.13.3","1.13.4","1.13.5","1.13.6","1.13.7","1.13.8","1.13.9","1.14.0","1.14.0.rc1","1.14.1","1.14.2","1.14.3","1.14.4","1.14.5","1.15.0","1.15.1","1.15.2","1.15.3","1.15.4","1.15.5","1.15.6","1.15.7","1.16.0","1.16.0.rc1","1.16.1","1.16.2","1.16.3","1.16.4","1.16.5","1.16.6","1.16.7","1.16.8","1.17.0","1.17.1","1.17.2","1.18.0","1.18.0.rc1","1.18.1","1.18.10","1.18.2","1.18.3","1.18.4","1.18.5","1.18.6","1.18.7","1.18.8","1.18.9","1.19.0","1.19.1","1.19.2","1.2.0","1.2.1","1.2.2","1.2.3","1.3.0","1.3.1","1.3.2","1.3.3","1.4.0","1.4.1","1.4.2","1.4.2.1","1.4.3","1.4.3.1","1.4.4","1.4.4.1","1.4.4.2","1.4.5","1.4.6","1.4.7","1.5.0","1.5.0.beta.1","1.5.0.beta.2","1.5.0.beta.3","1.5.0.beta.4","1.5.1","1.5.1.rc1","1.5.10","1.5.11","1.5.2","1.5.3","1.5.3.rc2","1.5.3.rc3","1.5.3.rc4","1.5.3.rc5","1.5.3.rc6","1.5.4","1.5.4.rc1","1.5.4.rc2","1.5.4.rc3","1.5.5","1.5.5.rc1","1.5.5.rc2","1.5.5.rc3","1.5.6","1.5.6.rc1","1.5.6.rc2","1.5.6.rc3","1.5.7","1.5.7.rc1","1.5.7.rc2","1.5.7.rc3","1.5.8","1.5.9","1.6.0","1.6.0.rc1","1.6.1","1.6.2","1.6.2.1","1.6.2.rc1","1.6.2.rc2","1.6.2.rc3","1.6.3","1.6.3.1","1.6.3.rc1","1.6.3.rc2","1.6.3.rc3","1.6.4","1.6.4.1","1.6.5","1.6.6.1","1.6.6.2","1.6.6.3","1.6.6.4","1.6.7","1.6.7.1","1.6.7.2","1.6.7.rc2","1.6.7.rc3","1.6.7.rc4","1.6.8","1.6.8.1","1.6.8.rc1","1.6.8.rc2","1.6.8.rc3","1.7.0","1.7.0.1","1.7.1","1.7.2","1.8.0","1.8.1","1.8.2","1.8.3","1.8.4","1.8.5","1.9.0","1.9.0.rc1","1.9.1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:14.04:LTS","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.5.9-2","1.5.9-3","1.6.0-1","1.6.1+ds-1","1.6.1+ds-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:16.04:LTS","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6.6.2+ds-2build2","1.6.6.3-1","1.6.7-1","1.6.7.1-1","1.6.7.2-3","1.6.7.2-3build1","1.6.7.2-3ubuntu0.1"]},{"source":"osv","ecosystem":"Ubuntu:18.04:LTS","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.8.0-1","1.8.1-1","1.8.1-1build1","1.8.2-1build1","1.8.2-1ubuntu0.1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:20.04:LTS","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.10.3+dfsg1-2","1.10.4+dfsg1-1","1.10.7+dfsg1-1","1.10.7+dfsg1-2","1.10.7+dfsg1-2build1","1.10.7+dfsg1-2ubuntu0.1~esm2"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.11.1+dfsg-2ubuntu1","1.11.7+dfsg-3","1.11.7+dfsg-3build1","1.13.1+dfsg-2","1.13.1+dfsg-2ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:24.04:LTS","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.14.3+dfsg-2","1.16.2+dfsg-1","1.16.2+dfsg-1build1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"ruby-nokogiri","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.18.2+dfsg-1build1","1.18.10+dfsg-2","1.18.10+dfsg-3"]}],"products":[{"vendor":"nokogiri","product":"nokogiri"},{"vendor":"sparklemotion","product":"nokogiri"}],"references":[{"url":"https://github.com/sparklemotion/nokogiri/security/advisories/GHSA-v2fc-qm4h-8hqv","tags":["vendor-advisory","Vendor Advisory","advisory","web","report"]},{"url":"https://www.vulncheck.com/advisories/nokogiri-before-memory-leak-via-xslt-transform","tags":["third-party-advisory","Third Party Advisory","advisory","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-79771","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-rh9x-7xjc-vwx2"},{"url":"https://github.com/advisories/GHSA-v2fc-qm4h-8hqv"},{"url":"https://docs.bell-sw.com/security/cves/CVE-2026-79771","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79771.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-79771","tags":["advisory"]},{"url":"https://github.com/sparklemotion/nokogiri","tags":["package"]},{"url":"https://ubuntu.com/security/CVE-2026-79771","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-79771","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-79771","title":"Nokogiri before 1.19.3 Memory Leak via XSLT Transform","description":"Nokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","status":"published","published":"2026-08-25T15:16:03.736Z","modified":"2026-08-25T17:44:08.629Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T13:50:27.582139Z"}],"euvd":[{"id":"EUVD-2026-65529","description":"Nokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","status":"published","published":"2026-08-25T15:16:03Z","modified":"2026-08-25T17:44:08Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T18:01:32.174502Z"}],"ghsa":[{"id":"GHSA-rh9x-7xjc-vwx2","title":"Duplicate Advisory: Nokogiri XSLT transform has a memory leak","description":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-v2fc-qm4h-8hqv. This link is maintained to preserve external references.\n\n## Original Description\nNokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","status":"withdrawn","published":"2026-08-25T18:31:52Z","modified":"2026-09-02T14:42:44Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/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"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T14:41:10.121131Z"},{"id":"GHSA-v2fc-qm4h-8hqv","title":"Nokogiri XSLT transform has a memory leak","description":"## Summary\n\nNokogiri's `Nokogiri::XSLT::Stylesheet#transform` leaks a small heap allocation when passed a Ruby string parameter containing a null byte.\n\nFor applications that pass attacker-controlled input through `XSLT.transform` parameters, this may be a vector for a denial of service attack against long-running processes.\n\n\n## Mitigation\n\nUpgrade to Nokogiri `\u003e= 1.19.3`.\n\nUsers may also be able to mitigate this issue without upgrading by validating untrusted transform parameters before passing them to `Nokogiri::XSLT::Stylesheet#transform`.\n\n\n## Severity\n\nThe Nokogiri maintainers have evaluated this as **Moderate Severity**, CVSS 5.3.\n\nEach leaked allocation is approximately 24–32 bytes, so meaningful memory growth requires sustained attacker-controlled traffic at high call rates. The bug does not cause memory corruption, information disclosure, or any change in the behavior of the transform itself, and the string-handling exception is raised as expected.\n\nApplications that do not pass raw attacker-controlled bytes to XSLT parameters are unlikely to be affected in practice.\n\n\n## Resources\n\n- [CWE-401: Missing Release of Memory after Effective Lifetime](https://cwe.mitre.org/data/definitions/401.html)\n\n\n## Credit\n\nThis vulnerability was responsibly reported by @Captainjack-kor.","status":"published","published":"2026-05-06T18:27:38Z","modified":"2026-09-02T14:43:00Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T14:41:10.121131Z"}],"nvd":[{"id":"CVE-2026-79771","description":"Nokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","status":"published","published":"2026-08-25T16:17:28.603Z","modified":"2026-09-01T14:55:10.577Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/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"},{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T14:12:41.347728Z"}],"osv":[{"id":"BELL-CVE-2026-79771","status":"published","published":"2026-09-03T06:05:30.384104Z","modified":"2026-09-17T07:15:05.856677297Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-02T15:28:26.041478Z"},{"id":"CVE-2026-79771","title":"Nokogiri before 1.19.3 Memory Leak via XSLT Transform","description":"Nokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","status":"published","published":"2026-08-25T15:16:03.736Z","modified":"2026-10-28T02:31:13.976132241Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T15:45:17.44708Z"},{"id":"DEBIAN-CVE-2026-79771","description":"Nokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","status":"published","published":"2026-08-25T16:17:28.603Z","modified":"2026-10-01T03:03:47.264606561Z","cvss":[{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/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":"2026-11-02T15:46:04.001673Z"},{"id":"GHSA-rh9x-7xjc-vwx2","title":"Duplicate Advisory: Nokogiri XSLT transform has a memory leak","description":"## Duplicate Advisory\n\nThis advisory has been withdrawn because it is a duplicate of GHSA-v2fc-qm4h-8hqv. This link is maintained to preserve external references.\n\n## Original Description\nNokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","status":"withdrawn","published":"2026-08-25T18:31:52Z","modified":"2026-09-10T03:51:14.628825282Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"},{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/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"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T15:46:55.877614Z"},{"id":"GHSA-v2fc-qm4h-8hqv","title":"Nokogiri XSLT transform has a memory leak","description":"## Summary\n\nNokogiri's `Nokogiri::XSLT::Stylesheet#transform` leaks a small heap allocation when passed a Ruby string parameter containing a null byte.\n\nFor applications that pass attacker-controlled input through `XSLT.transform` parameters, this may be a vector for a denial of service attack against long-running processes.\n\n\n## Mitigation\n\nUpgrade to Nokogiri `\u003e= 1.19.3`.\n\nUsers may also be able to mitigate this issue without upgrading by validating untrusted transform parameters before passing them to `Nokogiri::XSLT::Stylesheet#transform`.\n\n\n## Severity\n\nThe Nokogiri maintainers have evaluated this as **Moderate Severity**, CVSS 5.3.\n\nEach leaked allocation is approximately 24–32 bytes, so meaningful memory growth requires sustained attacker-controlled traffic at high call rates. The bug does not cause memory corruption, information disclosure, or any change in the behavior of the transform itself, and the string-handling exception is raised as expected.\n\nApplications that do not pass raw attacker-controlled bytes to XSLT parameters are unlikely to be affected in practice.\n\n\n## Resources\n\n- [CWE-401: Missing Release of Memory after Effective Lifetime](https://cwe.mitre.org/data/definitions/401.html)\n\n\n## Credit\n\nThis vulnerability was responsibly reported by @Captainjack-kor.","status":"published","published":"2026-05-06T18:27:38Z","modified":"2026-09-10T03:50:47.698230799Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T15:46:56.639206Z"},{"id":"UBUNTU-CVE-2026-79771","description":"Nokogiri versions before 1.19.3 contain a memory leak in the XSLT Stylesheet transform method when processing Ruby strings containing null bytes. Attackers can exploit this by passing attacker-controlled input with null bytes to transform parameters, causing heap allocations to leak and enabling denial of service against long-running processes.","status":"published","published":"2026-08-25T16:17:00Z","modified":"2026-09-02T19:36:46.909382795Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"},{"version":"4.0","score":6.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T16:57:18.015985Z"}]}}