CVE-2026-87910: python software foundation cpython Path Traversal

Vulnerability summary

CVE-2026-87910 is a medium (CVSS 5.7) Path Traversal vulnerability in python software foundation cpython. EPSS estimates a 0.50% chance of exploitation in the next 30 days, higher than 41.5% of scored vulnerabilities.

Timeline

1. 11-09-2026
   PublishedVulnerability first disclosed.
2. 03-10-2026
   Last modifiedVulnerability information updated.

Description

When tarfile extracts a link on a system that doesn't support links, it falls back to extracting a member from the archive. In this case, the filter function is run twice: once for the extracted member, and once with name set to the location of the link. For one of the calls, the return value was ignored. Instead, the member should be skipped if either call returns None.

• CWE-22Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.
• CWE-59Improper Link Resolution Before File Access ('Link Following')The product attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.