{"id":"CVE-2026-112021","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-112021","generatedAt":"2026-10-28T09:25:57.833Z","title":"snac2 before 2.93 contains a heap-based buffer overflow vulnerability in _xs_json_load_lexer() that allows unauthenticated remote attackers to corrupt heap memory by sending JSON strings containing a \\u0000 escape.","description":"snac2 before 2.93 contains a heap-based buffer overflow vulnerability in _xs_json_load_lexer() that allows unauthenticated remote attackers to corrupt heap memory by sending JSON strings containing a \\u0000 escape. Attackers can send a single crafted application/activity+json POST to activitypub_post_handler(), which parses it before signature checks, overflowing heap allocations and crashing the server.","published":"2026-10-18T12:17:15.000Z","lastModified":"2026-10-19T21:14:14.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/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/M"},"cwe":["CWE-122"],"affected":[],"epss":{"score":0.0067,"percentile":0.5178,"date":"2026-10-27","history":[{"date":"2026-10-19","score":0.0067,"percentile":0.51081}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.67%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-10-18T12:17:15.000Z","detail":{"score":"8.7","severity":"HIGH","publishedAt":"2026-10-18T12:17:15.200Z"},"summary":"New CVE, high severity (CVSS 8.7)."}],"references":[{"url":"https://codeberg.org/grunfink/snac2","source":"disclosure@vulncheck.com"},{"url":"https://codeberg.org/grunfink/snac2/commit/ec2c5c2046e0381bc942ec5d0d05ec861fe377e7","source":"disclosure@vulncheck.com"},{"url":"https://codeberg.org/grunfink/snac2/releases/tag/2.93","source":"disclosure@vulncheck.com"},{"url":"https://codeberg.org/grunfink/snac2/src/tag/2.92/xs_json.h#L283-L285","source":"disclosure@vulncheck.com"},{"url":"https://gist.github.com/nullenvk/2bf288e2d34cb3d4b7143e61dbf7d90b","source":"disclosure@vulncheck.com"},{"url":"https://nullenvk.pl/posts/02-snac2-json","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/snac2-before-2.93-heap-based-buffer-overflow-via-json-parser-xs-json-load-lexer","source":"disclosure@vulncheck.com"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-112021","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}