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4.3 Medium

CVE-2026-6103 phar_tar_number() parses the octal size field of a TAR header into a uint32_t with no overflow check

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 and versions

Product Affected versions Fixed in
PHP 8.5 earliest → < 8.5.11 8.5.11
PHP 8.4 earliest → < 8.4.26 8.4.26
PHP 8.3 earliest → < 8.3.35 8.3.35
PHP 8.2 earliest → < 8.2.34 8.2.34

References

Timeline

  1. Published
  2. Last modified

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