PHP security advisory

Windows reserved device names accepted in paths

CVE-2026-17545Not rated Published Filesystem functions on Windows

On Windows, reserved device names such as CON or NUL are not rejected in file paths, which can cause unexpected file operations.

Affected versions

BranchAffectedFixed in
PHP 8.5< 8.5.118.5.11
PHP 8.4< 8.4.268.4.26
PHP 8.3< 8.3.358.3.35
PHP 8.2< 8.2.348.2.34

Older branches: not assessed

Exploitation conditions

  • Windows only

Remediation

Upgrade to 8.2.34, 8.3.35, 8.4.26, 8.5.11 or a later release of your branch. If your branch is end-of-life, move to a supported branch. Distribution packages may carry a backported fix under an older version number; confirm with your vendor's security tracker.

A version number alone cannot prove patch status. Linux distributions and hosting providers often backport security fixes without changing the version. Check your vendor’s changelog.

Severity scores

No CVSS score recorded in our dataset yet. Check NVD for the latest scoring.

References

Data provenance

Secondary sources · pending primary verification

Last reviewed: Oct 24, 2026 · Source

Notes: Assembled from secondary sources (distribution trackers, release coverage). Publication date reflects the upstream fix release. Severity not yet verified unless a score is listed.