{"id":"CVE-2026-13713","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-13713","generatedAt":"2026-10-27T23:08:32.118Z","title":"YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack.","description":"YAML::Syck versions before 1.47 for Perl allow a use-after-free and double-free via an anchor node freed while still on the parser value stack.\n\nIn the bundled libsyck, when an anchor name is redefined or removed, syck_hdlr_add_anchor and syck_hdlr_remove_anchor free the node stored under that name with syck_free_node. That node can still be live on the parser's value stack, so syck_hdlr_add_node reaches it again and frees it a second time. On a normal build the 48-byte node chunk is freed twice and the interpreter aborts. Anchors need no special flags, so this is reached on the default Load path, and a 7-byte document that redefines an anchor triggers it.\n\nAny caller that runs Load or LoadFile on an untrusted document that redefines an anchor mid-parse crashes the interpreter, a denial of service.","published":"2026-07-16T22:17:00.000Z","lastModified":"2026-10-24T20:10:00.000Z","status":"Deferred","sourceIdentifier":"9b29abf9-4ab0-4765-b253-1875cd9b441e","cvss":{"version":"3.1","score":6.2,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"},"cwe":["CWE-415","CWE-416"],"affected":[],"epss":{"score":0.00179,"percentile":0.0737,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.18%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://github.com/toddr/YAML-Syck/commit/44c90a109ec3215ee7ce747bd11209835e123d8b.patch","source":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/TODDR/YAML-Syck-1.47/changes","source":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"http://www.openwall.com/lists/oss-security/2026/07/17/1","source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-13713","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."}