MEDIUM 5.3 Microsoft

CVE-2025-12781

base64.b64decode() always accepts "+/" characters, despite setting altchars

Microsoft Security Update 2026-Jan: base64.b64decode() always accepts "+/" characters, despite setting altchars

Affected Products

azl3 python-py 1.11.0-1 on Azure Linux 3.0

References

https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-12781
https://nvd.nist.gov/vuln/detail/CVE-2025-12781

Published: 2026-01-13 · Source: Microsoft · Feed updated: 2026-10-22

This medium severity vulnerability with a CVSS score of 5.3 was published on 2026-01-13 via Microsoft. Affected: azl3 python-py 1.11.0-1 on Azure Linux 3.0.

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