Medium [CVE-2026-13346] Arbitrary file installation via 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. A flaw was found in pip.

When processing doubly-encoded package URLs from malicious package indexes, pip incorrectly handles the file paths. A remote attacker could exploit this by convincing a user to download or install a package from such an index.

This could allow for files to be installed to arbitrary locations on the system, potentially leading to system compromise. Red Hat severity: Moderate — CVSS 5.9 (CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:H/A:L).

Weakness: CWE-22. Affected Red Hat products: Red Hat Hardened Images; Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat OpenShift Container Platform 4.

Red Hat fixing advisory: RHSA-2026:48788.

Affected products named by the advisory: Red Hat package: python-pip.