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{"cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-4177", "lastModified": "2026-03-17T14:20:01.670", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.1, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 5.2, "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "type": "Secondary"}]}, "published": "2026-03-16T23:16:21.543", "references": [{"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "url": "https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch"}, {"source": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "url": "https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21"}, {"source": "af854a3a-2127-422b-91ae-364da2661108", "url": "http://www.openwall.com/lists/oss-security/2026/03/16/6"}], "sourceIdentifier": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-122"}], "source": "9b29abf9-4ab0-4765-b253-1875cd9b441e", "type": "Secondary"}]}

{"bugzilla": {"description": "perl-YAML-Syck: YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter", "id": "2448277", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2448277"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.3", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L", "status": "draft"}, "cwe": "CWE-120", "details": ["Multiple security issues have been discovered in the perl YAML::Syck module. A heap overflow occurs when class names exceed the initial 512-byte allocation, a base64 decoder could read past the buffer end on trailing newlines. strtok mutated n->type_id in place, corrupting shared node data, and a 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."], "mitigation": {"lang": "en:us", "value": "Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability."}, "name": "CVE-2026-4177", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "perl-YAML-Syck", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Affected", "package_name": "perl-YAML-Syck", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "perl-YAML-Syck", "product_name": "Red Hat Enterprise Linux 8"}], "public_date": "2026-03-16T22:30:25Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-4177\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-4177\nhttps://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch\nhttps://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21"], "threat_severity": "Important"}