CVE-2026-6103
Description
phar_tar_number() parses the octal size field of a TAR header into a uint32_t with no overflow check. The field is 11 octal digits wide and holds values up to 0x1FFFFFFFF, so a size above 0xFFFFFFFF silently wraps. The parser then skips the wrong number of data blocks and interprets attacker-controlled file content as the next TAR header, which lets a crafted archive inject entries that PharData reports and extracts as if they were genuine.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
OS impact
Debian Affected 4 releases
| Version | Status | Fixed in |
|---|---|---|
| trixie | Affected | — |
| sid | Affected | — |
| forky | Affected | — |
| bookworm | Affected | — |
Alpine Fixed 1 release
| Version | Status | Fixed in |
|---|---|---|
| v3.24 | Fixed | 8.3.35-r0 |
References
- https://security-tracker.debian.org/tracker/CVE-2026-6103
- https://security.alpinelinux.org/vuln/CVE-2026-6103
- https://pkgs.alpinelinux.org/packages?name=php83
- https://pkgs.alpinelinux.org/packages?name=php84
- https://pkgs.alpinelinux.org/packages?name=php85
- https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85
CWEs
CWE-190
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.