Critical 9.1Published Mar 16, 2026

CVE-2026-4177YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter

Updated under an hour ago (Oct 27, 2026, 5:23 AM ET)

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It affects TODDR YAML::Syck and 3 other products. Add what you run to find out whether that includes you.

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Every CVE for TODDR YAML::Syck

Exploited in the last 30 days

YAML::Syck versions through 1.36 for Perl has several potential security vulnerabilities including a high-severity heap buffer overflow in the YAML emitter. The heap overflow occurs when class names exceed the initial 512-byte allocation. The base64 decoder could read past the buffer end on trailing newlines. strtok mutated n->type_id in place, corrupting shared node data. 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.

CVSS: 9.1 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H
Weakness (CWE): CWE-122, CWE-120
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: CPANSec
NVD analysis: Modified
Record last updated: Jul 14, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

TODDR YAML::Syck toddr:yaml_syck (from the name)	through 1.36	CNA record
Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support redhat:rhel_els	from 0:1.27-3.el7_9.1 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8 redhat:enterprise_linux	from 0:1.30-6.el8_10 not affected	CISA ADP
toddr yaml::syck toddr:yaml::syck	before 1.37	NVD

References

References

https://github.com/cpan-authors/YAML-Syck/commit/e8844a31c8cf0052914b198fc784ed4e6b8ae69e.patch	patch
https://metacpan.org/release/TODDR/YAML-Syck-1.37_01/changes#L21	release-notes
http://www.openwall.com/lists/oss-security/2026/03/16/6	mailing-list, third-party-advisory
https://access.redhat.com/errata/RHSA-2026:6470
https://access.redhat.com/errata/RHSA-2026:8311
https://access.redhat.com/security/cve/CVE-2026-4177
https://bugzilla.redhat.com/show_bug.cgi?id=2448277
https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-4177.json

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.