{"id":"CVE-2026-32874","aliases":["ALPINE-CVE-2026-32874","DEBIAN-CVE-2026-32874","EUVD-2026-13443","GHSA-wgvc-ghv9-3pmm","MGASA-2026-0073","PYSEC-2026-2291","ROOT-APP-PYPI-CVE-2026-32874","UBUNTU-CVE-2026-32874","USN-8219-1"],"status":"published","title":"UltraJSON has a Memory Leak parsing large integers allows DoS","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00508,"percentile":0.4375,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-401","CWE-772"],"published":"2026-03-18T13:01:15Z","modified":"2026-11-03T06:33:02Z","fixes":[{"ecosystem":"PyPI","package":"ujson","fixed_in":["5.12.0"],"sources":["ghsa","osv"]},{"ecosystem":"Alpine:v3.23","package":"py3-ujson","fixed_in":["5.12.0-r0"],"sources":["osv"]},{"ecosystem":"Alpine:v3.24","package":"py3-ujson","fixed_in":["5.12.0-r0"],"sources":["osv"]},{"ecosystem":"Debian:14","package":"ujson","fixed_in":["5.13.0-1"],"sources":["osv"]},{"ecosystem":"Root:PyPI","package":"ujson","fixed_in":["5.10.0+aikido.5","5.11.0+aikido.2","5.8.0+aikido.4","5.11.0+aikido.3","5.10.0+aikido.6","5.8.0+aikido.5","5.8.0+aikido.6","5.10.0+aikido.7","5.11.0+aikido.4"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:24.04:LTS","package":"ujson","fixed_in":["5.9.0-1ubuntu0.1~esm1"],"sources":["osv"]},{"ecosystem":"Ubuntu:25.10","package":"ujson","fixed_in":["5.10.0-1ubuntu0.1"],"sources":["osv"]},{"ecosystem":"Ubuntu:26.04:LTS","package":"ujson","fixed_in":["5.11.0-3ubuntu0.1"],"sources":["osv"]},{"ecosystem":"Ubuntu:Pro:22.04:LTS","package":"ujson","fixed_in":["5.1.0-1ubuntu0.1~esm2"],"sources":["osv"]}],"affected":[{"source":"ghsa","ecosystem":"PyPI","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.4.0"},{"last_affected":"5.11.0"},{"fixed":"5.12.0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.23","package":"py3-ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.12.0-r0"}]}]},{"source":"osv","ecosystem":"Alpine:v3.24","package":"py3-ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.12.0-r0"}]}]},{"source":"osv","ecosystem":"Debian:12","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.10.0-1","5.11.0-1","5.11.0-2","5.11.0-3","5.13.0-1","5.7.0-1","5.8.0-1","5.9.0-1"]},{"source":"osv","ecosystem":"Debian:13","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.10.0-1","5.11.0-1","5.11.0-2","5.11.0-3","5.13.0-1"]},{"source":"osv","ecosystem":"Debian:14","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.13.0-1"}]}],"versions":["5.10.0-1","5.11.0-1","5.11.0-2","5.11.0-3"]},{"source":"osv","ecosystem":"PyPI","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.4.0"},{"fixed":"5.12.0"}]}],"versions":["5.10.0","5.11.0","5.4.0","5.5.0","5.6.0","5.7.0","5.8.0","5.9.0"]},{"source":"osv","ecosystem":"Mageia:9","package":"python-ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.7.0-1.1.mga9"}]}],"bundled":2},{"source":"osv","ecosystem":"PyPI","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.4.0"},{"fixed":"5.12.0"}]}],"versions":["5.10.0","5.11.0","5.4.0","5.5.0","5.6.0","5.7.0","5.8.0","5.9.0"]},{"source":"osv","ecosystem":"Root:PyPI","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.0+aikido.5"},{"fixed":"5.11.0+aikido.2"},{"fixed":"5.8.0+aikido.4"},{"fixed":"5.11.0+aikido.3"},{"fixed":"5.10.0+aikido.6"},{"fixed":"5.8.0+aikido.5"},{"fixed":"5.8.0+aikido.6"},{"fixed":"5.10.0+aikido.7"},{"fixed":"5.11.0+aikido.4"}]}]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.9.0-1ubuntu0.1~esm1"}]}],"versions":["5.8.0-1","5.8.0-1build1","5.9.0-1","5.9.0-1build1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.0-1ubuntu0.1"}]}],"versions":["5.10.0-1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.10","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["5.11.0-3build1","5.13.0-1"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.11.0-3ubuntu0.1"}]}],"versions":["5.10.0-1build2","5.10.0-1build3","5.11.0-3","5.11.0-3build1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:22.04:LTS","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.1.0-1ubuntu0.1~esm2"}]}],"versions":["4.0.2-1","4.0.2-1build1","4.2.0-1","5.1.0-1","5.1.0-1build1","5.1.0-1ubuntu0.1~esm1"]},{"source":"osv","ecosystem":"Ubuntu:Pro:24.04:LTS","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.9.0-1ubuntu0.1~esm1"}]}],"versions":["5.8.0-1","5.8.0-1build1","5.9.0-1","5.9.0-1build1"]},{"source":"osv","ecosystem":"Ubuntu:25.10","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.0-1ubuntu0.1"}]}],"versions":["5.10.0-1build2"]},{"source":"osv","ecosystem":"Ubuntu:26.04:LTS","package":"ujson","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.11.0-3ubuntu0.1"}]}],"versions":["5.10.0-1build2","5.10.0-1build3","5.11.0-3","5.11.0-3build1"]}],"products":[{"vendor":"red hat","product":"red hat openstack platform 16.2"},{"vendor":"red hat","product":"red hat openstack platform 17.1"},{"vendor":"red hat","product":"red hat openstack platform 18.0"},{"vendor":"ultrajson","product":"ultrajson"},{"vendor":"ultrajson_project","product":"ultrajson"}],"references":[{"url":"https://github.com/ultrajson/ultrajson/security/advisories/GHSA-wgvc-ghv9-3pmm","tags":["x_refsource_CONFIRM","Vendor Advisory","advisory","web","report"]},{"url":"https://github.com/ultrajson/ultrajson/commit/4baeb950df780092bd3c89fc702a868e99a3a1d2","tags":["x_refsource_MISC","Patch","fix","web","report"]},{"url":"https://github.com/ultrajson/ultrajson/releases/tag/5.12.0","tags":["x_refsource_MISC","Product","Release Notes","web","advisory","report"]},{"url":"https://access.redhat.com/security/cve/CVE-2026-32874","tags":["vdb-entry","x_refsource_REDHAT","advisory","web"]},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2449411","tags":["issue-tracking","x_refsource_REDHAT","report"]},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-32874.json","tags":["x_sadp-csaf-vex","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-32874","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-wgvc-ghv9-3pmm"},{"url":"https://security.alpinelinux.org/vuln/CVE-2026-32874","tags":["advisory"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/32xxx/CVE-2026-32874.json","tags":["advisory"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-32874","tags":["advisory"]},{"url":"https://github.com/ultrajson/ultrajson","tags":["package"]},{"url":"https://advisories.mageia.org/MGASA-2026-0073.html","tags":["advisory"]},{"url":"https://bugs.mageia.org/show_bug.cgi?id=35258","tags":["report"]},{"url":"https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3FAXR2DP4Q5GMDURV7CAFQ5YGYAOMVNL/","tags":["web"]},{"url":"https://ubuntu.com/security/CVE-2026-32874","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-32874","tags":["report"]},{"url":"https://ubuntu.com/security/notices/USN-8219-1","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-32875","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-32874","title":"UltraJSON has a Memory Leak parsing large integers allows DoS","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","status":"published","published":"2026-03-20T01:31:30.207Z","modified":"2026-07-15T01:07:33.77Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-401","CWE-772"],"updated_at":"2026-11-02T14:19:57.47301Z"}],"euvd":[{"id":"EUVD-2026-13443","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","status":"published","published":"2026-03-20T01:31:30Z","modified":"2026-07-15T01:07:33Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T18:19:56.47701Z"}],"ghsa":[{"id":"GHSA-wgvc-ghv9-3pmm","title":"UltraJSON has a Memory Leak parsing large integers allows DoS ","description":"#### Summary\n\nujson 5.4.0 to 5.11.0 inclusive contain an accumulating memory leak in JSON parsing _large_ (outside of the range [-2^63, 2^64 - 1]) integers.\n\n#### Exploitability\n\nAny service that calls `ujson.load()`/`ujson.loads()`/`ujson.decode()` on untrusted inputs is affected and vulnerable to denial of service attacks.\n\n#### Details\n\nThe leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than `sys.get_int_max_str_digits()` digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload.\n\n```python\nujson.loads(str(2 ** 64 - 1))  # No leak\nujson.loads(str(2 ** 64))  # Leaks\nujson.loads(str(10 ** sys.get_int_max_str_digits()))  # Leaks and raises ValueError\n```\n\n#### Fix\n\nThe leak is fixed in `ujson 5.12.0` (4baeb950df780092bd3c89fc702a868e99a3a1d2). There are no workarounds beyond upgrading to an unaffected version.\n\n#### Credits\n\nDiscovered by Cameron Criswell/Skevros using Coverage-guided fuzzing (libFuzzer + AddressSanitizer)","status":"published","published":"2026-03-18T13:01:15Z","modified":"2026-03-20T21:19:51Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T14:39:39.567266Z"}],"nvd":[{"id":"CVE-2026-32874","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","status":"published","published":"2026-03-20T02:16:35.703Z","modified":"2026-07-15T02:20:01.79Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-401","CWE-772"],"updated_at":"2026-11-02T14:12:10.126802Z"}],"osv":[{"id":"ALPINE-CVE-2026-32874","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","status":"published","published":"2026-03-20T02:16:35.703Z","modified":"2026-11-03T06:33:02.357330483Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T07:15:53.944853Z"},{"id":"CVE-2026-32874","title":"UltraJSON has a Memory Leak parsing large integers allows DoS","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","status":"published","published":"2026-03-20T01:31:30.207Z","modified":"2026-10-28T10:49:22.586765176Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T15:45:01.548715Z"},{"id":"DEBIAN-CVE-2026-32874","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","status":"published","published":"2026-03-20T02:16:35.703Z","modified":"2026-10-01T03:03:10.4471254Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:45:54.587575Z"},{"id":"GHSA-wgvc-ghv9-3pmm","title":"UltraJSON has a Memory Leak parsing large integers allows DoS ","description":"#### Summary\n\nujson 5.4.0 to 5.11.0 inclusive contain an accumulating memory leak in JSON parsing _large_ (outside of the range [-2^63, 2^64 - 1]) integers.\n\n#### Exploitability\n\nAny service that calls `ujson.load()`/`ujson.loads()`/`ujson.decode()` on untrusted inputs is affected and vulnerable to denial of service attacks.\n\n#### Details\n\nThe leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than `sys.get_int_max_str_digits()` digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload.\n\n```python\nujson.loads(str(2 ** 64 - 1))  # No leak\nujson.loads(str(2 ** 64))  # Leaks\nujson.loads(str(10 ** sys.get_int_max_str_digits()))  # Leaks and raises ValueError\n```\n\n#### Fix\n\nThe leak is fixed in `ujson 5.12.0` (4baeb950df780092bd3c89fc702a868e99a3a1d2). There are no workarounds beyond upgrading to an unaffected version.\n\n#### Credits\n\nDiscovered by Cameron Criswell/Skevros using Coverage-guided fuzzing (libFuzzer + AddressSanitizer)","status":"published","published":"2026-03-18T13:01:15Z","modified":"2026-09-10T03:50:41.558110605Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-401"],"updated_at":"2026-11-02T15:46:58.767335Z"},{"id":"PYSEC-2026-2291","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","status":"published","published":"2026-03-20T02:16:35.703Z","modified":"2026-07-13T07:15:45.403362007Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:52:55.537808Z"},{"id":"ROOT-APP-PYPI-CVE-2026-32874","title":"CVE-2026-32874 in ujson - Patched by Root","description":"Root has patched CVE-2026-32874 in the ujson package for Root:PyPI. Multiple fixed versions available.","status":"published","published":"2026-10-07T06:41:24Z","modified":"2026-10-07T07:15:06.635601036Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T15:53:28.259095Z"},{"id":"UBUNTU-CVE-2026-32874","description":"UltraJSON is a fast JSON encoder and decoder written in pure C with bindings for Python 3.7+. Versions 5.4.0 through 5.11.0 contain an accumulating memory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1]) integers. The leaked memory is a copy of the string form of the integer plus an additional NULL byte. The leak occurs irrespective of whether the integer parses successfully or is rejected due to having more than sys.get_int_max_str_digits() digits, meaning that any sized leak per malicious JSON can be achieved provided that there is no limit on the overall size of the payload. Any service that calls ujson.load()/ujson.loads()/ujson.decode() on untrusted inputs is affected and vulnerable to denial of service attacks. This issue has been fixed in version 5.12.0.","status":"published","published":"2026-03-20T02:16:00Z","modified":"2026-10-17T12:59:58.458378319Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T16:56:16.036833Z"},{"id":"MGASA-2026-0073","title":"Updated python-ujson packages fix security vulnerabilities","description":"CVE-2026-32874 ujson 5.4.0 to 5.11.0 inclusive contains an accumulating\nmemory leak in JSON parsing large (outside of the range [-2^63, 2^64 - 1])\nintegers.\nujson 5.4.0 to 5.11.0 has an integer overflow while handling a large indent\nwhich leads to a buffer overflow or infinite loop.\n","status":"published","published":"2026-03-29T00:55:09Z","modified":"2026-04-16T04:42:16.221669775Z","updated_at":"2026-11-02T15:49:43.178336Z"},{"id":"USN-8219-1","title":"ujson vulnerabilities","description":"Cameron Criswell discovered that UltraJSON contained a memory leak\nthat would occur when parsing large integers. An attacker could\npossibly use this issue to cause UltraJSON to crash, resulting in a\ndenial of service. This issue only affected Ubuntu 24.04 LTS,\nUbuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-32874)\n\nIt was discovered that UltraJSON contained integer overflow/underflow\nissues when calculating how much memory to reserve for indentation in\ncertain instances. An attacker could possibly use this issue to cause\nUltraJSON to crash, resulting in a denial of service. (CVE-2026-32875)","status":"published","published":"2026-04-28T17:32:43Z","modified":"2026-06-30T18:15:55.859370459Z","updated_at":"2026-11-02T16:58:22.951676Z"}]}}