PHP security advisory

Integer overflow in Phar TAR size handling

CVE-2026-6103Not rated Published ext/phar

A crafted TAR-based phar archive can trigger an integer overflow when its size fields are processed.

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

  • Processing untrusted phar/TAR archives

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.