[ CVE-2026-6103 · Published 25 Sep 2026 ]
Vulnerability in PHP Group PHP
[ Why it matters ]Priority signals
- Public proof-of-concept exploit exists (CISA SSVC)
[ Description ]Official 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.
[ Fixes ]Fixes and patches
No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.
[ Advisories ]Government CERT advisories
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BSI CERT-BundWID-SEC-2026-3585
PHP: Multiple vulnerabilities Translated from German
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CERT-FRCERTFR-2026-AVI-1227
Multiple vulnerabilities in PHP Translated from French
Multiple vulnerabilities have been discovered in PHP. Some of them allow an attacker to cause remote denial of service, a breach of data confidentiality and a breach of data integrity.