CVE-2025-4516

MEDIUM EPSS 6.6%
Published May 15, 20251y ago · Modified Jun 17, 20262w ago
5.9 CVSS 4.0
Medium
Find Similar
Published May 15, 2025 1y ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
5.9
Exploitability
—
Impact
—
Vector string
CVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Local
Attack Complexity High
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
6.6% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-416 Use After Free Memory Safety

References 12

  • openwall.com http://www.openwall.com/lists/oss-security/2025/05/16/4
  • openwall.com http://www.openwall.com/lists/oss-security/2025/05/19/1
  • github.com https://github.com/python/cpython/commit/4398b788ffc1f954a2c552da285477d42a571292
  • github.com https://github.com/python/cpython/commit/6279eb8c076d89d3739a6edb393e43c7929b429d
  • github.com https://github.com/python/cpython/commit/69b4387f78f413e8c47572a85b3478c47eba8142
  • github.com https://github.com/python/cpython/commit/73b3040f592436385007918887b7e2132aa8431f
  • github.com https://github.com/python/cpython/commit/8d35fd1b34935221aff23a1ab69a429dd156be77
  • github.com https://github.com/python/cpython/commit/9f69a58623bd01349a18ba0c7a9cb1dad6a51e8e
  • github.com https://github.com/python/cpython/commit/ab9893c40609935e0d40a6d2a7307ea51aec598b
  • github.com https://github.com/python/cpython/issues/133767
  • github.com https://github.com/python/cpython/pull/129648
  • mail.python.org https://mail.python.org/archives/list/security-announce@python.org/thread/L75IPBBTSCYEF56I2M4KIW353BB3AY74/

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.