pip Arbitrary File Write via Doubly-Encoded URLs in Untrusted Index
CVE-2026-13346 Published on July 29, 2026
pip absolute path traversal during download from malicious package indexes
pip would incorrectly handle doubly-encoded package URLs from indexes allowing for files to be installed to arbitrary locations on disk even when installing wheels.
This vulnerability requires downloading or installing a package from a malicious package index to succeed, malicious packages alone are not able to exploit this vulnerability. Note that this vulnerability only materially impacts users running `pip download` with the `--only-binary` option as installing source distributions from an untrusted index is already an unsafe operation that executes code during install time.
Vulnerability Analysis
CVE-2026-13346 is exploitable with network access. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Type
Absolute Path Traversal
The software uses external input to construct a pathname that should be within a restricted directory, but it does not properly neutralize absolute path sequences such as "/abs/path" that can resolve to a location that is outside of that directory. This allows attackers to traverse the file system to access files or directories that are outside of the restricted directory.
Products Associated with CVE-2026-13346
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Affected Versions
Python Packaging Authority pip:- Before 26.2 is affected.