Use After Free Affecting python39-pyyaml package, versions <0:5.4.1-1.module+el8.9.0+19644+d68f775d


Severity

Recommended
high

Based on CentOS security rating.

Threat Intelligence

EPSS
0.17% (7th percentile)

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  • Snyk IDSNYK-CENTOS8-PYTHON39PYYAML-10652965
  • published7 Jul 2025
  • disclosed15 May 2025

Introduced: 15 May 2025

CVE-2025-4516  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Centos:8 python39-pyyaml to version 0:5.4.1-1.module+el8.9.0+19644+d68f775d or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream python39-pyyaml package and not the python39-pyyaml package as distributed by Centos. See How to fix? for Centos:8 relevant fixed versions and status.

There is an issue in CPython when using bytes.decode(&#34;unicode_escape&#34;, error=&#34;ignore|replace&#34;). If you are not using the "unicode_escape" encoding or an error handler your usage is not affected. To work-around this issue you may stop using the error= handler and instead wrap the bytes.decode() call in a try-except catching the DecodeError.

CVSS Base Scores

version 3.1