{"id":"CVE-2026-4177","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-4177","generatedAt":"2026-10-28T10:35:58.859Z","title":"YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.","description":"YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter.\n\nThe heap overflow occurs when class names exceed the initial 512-byte allocation.\n\nThe base64 decoder could read past the buffer end on trailing newlines.\n\nstrtok mutated n->type_id in place, corrupting shared node data.\n\nA memory leak occurred in syck_hdlr_add_anchor when a node already had an anchor. The incoming anchor string 'a' was leaked on early return.","published":"2026-03-16T23:16:22.000Z","lastModified":"2026-07-15T02:22:39.000Z","status":"Modified","sourceIdentifier":"9b29abf9-4ab0-4765-b253-1875cd9b441e","cvss":{"version":"3.1","score":9.1,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H"},"cwe":["CWE-122","CWE-120"],"affected":["toddr/yaml\\"],"epss":{"score":0.00445,"percentile":0.38561,"date":"2026-10-27","history":[]},"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 (0.45%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch","tags":["Patch"],"source":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21","tags":["Release Notes"],"source":"9b29abf9-4ab0-4765-b253-1875cd9b441e"},{"url":"http://www.openwall.com/lists/oss-security/2026/03/16/6","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://access.redhat.com/errata/RHSA-2026:6470","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/errata/RHSA-2026:8311","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://access.redhat.com/security/cve/CVE-2026-4177","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2448277","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4177.json","source":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-4177","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."}