Review reviewHigh

CVE-2025-4435

Python Software Foundation CPython

When using a TarFile.errorlevel = 0 and extracting with a filter the documented behavior is that any filtered members would be skipped and not extracted. However the actual behavior of TarFile.errorlevel = 0 in affected versions is that the member would still be extracted and not skipped.

CVSS
7.5
EPSS
0.52%
41.1% percentile
CISA KEV
Not listed
Published
2025.06.03
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.52%
Technical severityCVSS 7.5

Vulnerability overview

When using a TarFile.errorlevel = 0 and extracting with a filter the documented behavior is that any filtered members would be skipped and not extracted. However the actual behavior of TarFile.errorlevel = 0 in affected versions is that the member would still be extracted and not skipped.

Affected product and versions

Product
Python Software Foundation CPython
Affected versions
< 3.9.23, >= 3.10.0 < 3.10.18, >= 3.11.0 < 3.11.13, >= 3.12.0 < 3.12.11, >= 3.13.0 < 3.13.4, >= 3.14.0a1 < 3.14.0b3
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Python Software Foundation CPython and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE
CWE-682
CVE-2025-4435 — Python Software Foundation CPython | SECUFOCUS NOW