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CVE PROGRAM SOURCE RECORD4.3 Medium

CVE-2026-6103

Phar TAR phar_tar_number() Integer Overflow - Archive Entry Injection

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

PHP Group PHP

Default version status: unaffected

  • 8.2.* to < 8.2.34affected
  • 8.3.* to < 8.3.35affected
  • 8.4.* to < 8.4.26affected
  • 8.5.* to < 8.5.11affected

References