CVE-2025-4516 - CVE House
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Status published Medium CVE-2025-4516

Use-after-free in "unicode_escape" decoder with error handler

Vulnerability Description

There is an issue in CPython when using `bytes.decode("unicode_escape", error="ignore|replace")`. 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.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

No credits recorded in the NVD database.

Affected Vendor

Python Software Foundation

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Affected Software

CPython
Vulnerable Versions:
0, 3.11.0, 3.12.0, 3.13.0, 3.14.0a1

Timeline

Official Publish: May 15th, 2025
Last Modified: April 21st, 2026
Added to House: July 22nd, 2026

CVSS Vectors

Weaknesses (CWE)