CVE-2019-25777 — YAML versions before 1

YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.

01What is this vulnerability?

YAML versions before 1.27_001 for Perl allow a loaded perl/glob document to replace any package variable, which can lead to arbitrary code execution.

02Affected products

No structured affected-product list available — see references below for vendor advisories.

03Active exploitation status

Not currently listed on the CISA Known Exploited Vulnerabilities (KEV) catalog. EPSS is the best forward-looking signal — see the EPSS row above.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Ask SARA in chat to draft a starting detection for this CVE in your stack of choice.

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2026-10-05T07:16:29.557
• Last modified: 2026-10-06T17:17:09.893

09References

• github.com — https://github.com/ingydotnet/yaml-pm/commit/bace96b5e6661d521c7c515c94a09e081c9…
• github.com — https://github.com/ingydotnet/yaml-pm/issues/212
• metacpan.org — https://metacpan.org/release/TINITA/YAML-1.28/changes
• www.openwall.com — http://www.openwall.com/lists/oss-security/2026/10/05/7