Red Hat Security Advisory: perl-YAML-Syck security update
Affects Red Hat perl-YAML-SyckSource GCVE Database
Not known to be exploited · CVSS 9.1 Critical.
Data as of 2 Nov 2026, 02:43 UTC
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 16 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| TODDRYAML::Syck | Affected
| Fixed in– |
GitHubYAML-Syckpkg:github/YAML-SyckOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
AI-suggested
Red Hat has released security updates for perl-YAML-Syck in Red Hat Enterprise Linux 7 Extended Life Cycle Support. Users should apply the available updates as detailed in the Red Hat advisory (RHSA-2026:8311) and the referenced article (https://access.redhat.com/articles/11258) to remediate the vulnerability. No additional mitigation steps are indicated beyond applying the official patch.
Description
A high-severity heap buffer overflow vulnerability (CVE-2026-4177) exists in the perl-YAML-Syck module versions through 1.36. This module provides a Perl interface to the libsyck data serialization library, enabling conversion between Perl data structures and YAML strings. The vulnerability affects the YAML emitter component and could lead to memory corruption.