Vulnerability Details CVE-2026-6103
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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 4.3%
CVSS Severity
CVSS v3 Score 4.3
Products affected by CVE-2026-6103