{"id":"CVE-2026-6103","title":"phar_tar_number() parses the octal size field of a TAR header into a uint32_t with no overflow check","summary":"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 …","severity":"medium","cvss":4.3,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","cwe":["CWE-190"],"vendor":"PHP Group","product":"PHP","affected":["PHP >= 8.2.* < 8.2.34","PHP >= 8.3.* < 8.3.35","PHP >= 8.4.* < 8.4.26","PHP >= 8.5.* < 8.5.11"],"published":"2026-09-25","updated":"2026-09-25","sourceUpdated":"2026-09-25T21:17:23.790","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-6103","references":[{"url":"https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85","label":"security@php.net"},{"url":"https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85","label":"134c704f-9b21-4f2e-91b3-4a467353bcc0"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6103.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-6103"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2541638"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-6103"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6103"},{"url":"https://access.redhat.com/errata/RHSA-2026:70720"}],"tags":["nvd","cve.org","exploit-available","csaf","vex","red-hat"],"exploitAvailable":true,"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-09-25T20:41:05.626504Z"},"ingestedAt":"2026-09-25T21:19:40.145Z","patched":["hardened_images"],"slug":"CVE-2026-6103","body":"## Overview\n\nphar_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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **RHSA-2026:70720** · Red Hat · fixed in: Red Hat Hardened Images · released 2026-09-23 · [advisory](https://access.redhat.com/errata/RHSA-2026:70720)\n- **Red Hat VEX** · Moderate · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 7, Red Hat Enterprise Linux 8, … · updated 2026-09-25 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-6103.json)","depth":"twilight","depthScore":36,"depthScoreParts":{"impact":23.7,"likelihood":0,"exploitation":12,"ransomware":0},"changes":[]}