{"id":"CVE-2026-88351","aliases":["EUVD-2026-86022","GHSA-cmcq-v328-82vj","UBUNTU-CVE-2026-88351"],"status":"published","title":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms...","description":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms. When parsing a specially crafted MessagePack array32 or map32 object with an excessively large element count, the page allocation size calculation in mpack_tree_parse_children() can overflow size_t and produce an undersized allocation. Subsequent parsing writes mpack_node_data_t records beyond the allocated heap buffer, resulting in heap-buffer-overflow, memory corruption, and denial of service.","severity":{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-11","score":0.00389,"percentile":0.33468,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-190"],"published":"2026-09-24T00:00:00Z","modified":"2026-11-04T20:04:27Z","affected":[{"source":"osv","ecosystem":"Ubuntu:26.10","package":"mpack","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.6-19build1"]}],"references":[{"url":"https://github.com/ludocode/mpack/commit/3d54d1215bdb5478d3ddecaf85884c58b382cd9b","tags":["fix"]},{"url":"https://github.com/ludocode/mpack/issues/123","tags":["exploit","report"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-88351","tags":["advisory"]},{"url":"https://github.com/advisories/GHSA-cmcq-v328-82vj"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/88xxx/CVE-2026-88351.json","tags":["advisory"]},{"url":"https://ubuntu.com/security/CVE-2026-88351","tags":["report"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-88351","tags":["report"]}],"sources":{"cve":[{"id":"CVE-2026-88351","description":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms. When parsing a specially crafted MessagePack array32 or map32 object with an excessively large element count, the page allocation size calculation in mpack_tree_parse_children() can overflow size_t and produce an undersized allocation. Subsequent parsing writes mpack_node_data_t records beyond the allocated heap buffer, resulting in heap-buffer-overflow, memory corruption, and denial of service.","status":"published","published":"2026-09-24T00:00:00Z","modified":"2026-09-25T18:09:28.514Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"adp"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T13:41:53.237769Z"}],"euvd":[{"id":"EUVD-2026-86022","description":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms. When parsing a specially crafted MessagePack array32 or map32 object with an excessively large element count, the page allocation size calculation in mpack_tree_parse_children() can overflow size_t and produce an undersized allocation. Subsequent parsing writes mpack_node_data_t records beyond the allocated heap buffer, resulting in heap-buffer-overflow, memory corruption, and denial of service.","status":"published","published":"2026-09-24T00:00:00Z","modified":"2026-09-25T18:09:28Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T17:27:55.070935Z"}],"ghsa":[{"id":"GHSA-cmcq-v328-82vj","title":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms...","description":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms. When parsing a specially crafted MessagePack array32 or map32 object with an excessively large element count, the page allocation size calculation in mpack_tree_parse_children() can overflow size_t and produce an undersized allocation. Subsequent parsing writes mpack_node_data_t records beyond the allocated heap buffer, resulting in heap-buffer-overflow, memory corruption, and denial of service.","status":"published","published":"2026-09-24T15:31:36Z","modified":"2026-09-25T18:31:20Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T15:12:27.190195Z"}],"nvd":[{"id":"CVE-2026-88351","description":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms. When parsing a specially crafted MessagePack array32 or map32 object with an excessively large element count, the page allocation size calculation in mpack_tree_parse_children() can overflow size_t and produce an undersized allocation. Subsequent parsing writes mpack_node_data_t records beyond the allocated heap buffer, resulting in heap-buffer-overflow, memory corruption, and denial of service.","status":"published","published":"2026-09-24T15:17:50.423Z","modified":"2026-09-25T18:17:31.257Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"secondary"}],"cwes":["CWE-190"],"updated_at":"2026-11-02T14:12:51.036099Z"}],"osv":[{"id":"CVE-2026-88351","description":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms. When parsing a specially crafted MessagePack array32 or map32 object with an excessively large element count, the page allocation size calculation in mpack_tree_parse_children() can overflow size_t and produce an undersized allocation. Subsequent parsing writes mpack_node_data_t records beyond the allocated heap buffer, resulting in heap-buffer-overflow, memory corruption, and denial of service.","status":"published","published":"2026-09-24T00:00:00Z","modified":"2026-10-28T11:19:14.527262062Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-02T15:45:19.210277Z"},{"id":"UBUNTU-CVE-2026-88351","description":"An integer overflow vulnerability exists in the MPack Node API in MPack 1.1.1 on 32-bit platforms. When parsing a specially crafted MessagePack array32 or map32 object with an excessively large element count, the page allocation size calculation in mpack_tree_parse_children() can overflow size_t and produce an undersized allocation. Subsequent parsing writes mpack_node_data_t records beyond the allocated heap buffer, resulting in heap-buffer-overflow, memory corruption, and denial of service.","status":"published","published":"2026-09-24T15:17:00Z","modified":"2026-11-04T20:04:27.569873737Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"}],"updated_at":"2026-11-04T21:43:30.004651Z"}]}}