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Vulnerabilities

Vulnerability · CVE-2025-4516

There is an issue in CPython when using .

Published May 15, 2025 · catalog updated Jul 31, 2026 · Python Software Foundation CPython

Check if you run it

No confirmed exploitation is on record for CVE-2025-4516. EPSS is 0.22%. Act only if a listed version of Python Software Foundation CPython is installed.

Gaps on this record

  • No vendor fix or required action is stored. Compare the linked advisory before you change production.
Severity
Medium5.9
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.22%
Remediation
Version ranges on file
Affected products
vendor Python Software Foundation CPython 3.13.0 <3.13.4

There is an issue in CPython when using . 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.

Are you affected?

Enter the version you run. The result uses only the ranges stored on this record.

The check returns affected, not affected, or incomplete. It does not guess a version that is missing from the record.

  • vendor Python Software Foundation CPython 3.13.0 <3.13.43.13.0 <3.13.4

How to fix CVE-2025-4516

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2025-4516. EPSS is 0.22%. Act only if a listed version of Python Software Foundation CPython is installed.

Which versions are affected?

Compare what you have installed with Python Software Foundation CPython 3.13.0 <3.13.4 3.13.0 <3.13.4. Compare the installed version with the linked vendor advisory before you change production.

What should an analyst verify?

No weakness class is stored. EPSS 0.22%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. May 15, 2025 · EUVD

    Detected

    There is an issue in CPython when using . 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.

  2. Jul 31, 2026 · EUVD

    Updated

    There is an issue in CPython when using . 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.

Sources

  • CVE.orgVulnerability recordCVE-2025-4516

    Official CVE identifier

    cve.org
  • FIRST EPSSExploitation probabilityCVE-2025-4516

    30-day exploitation probability 0.2%

    first.org
  • EUVDVulnerability recordEUVD-2025-15156

    There is an issue in CPython when using . 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 Decod

    euvd.enisa.europa.eu

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.