{"schemaVersion":3,"id":"CVE-2026-6103","aliases":["UBUNTU-CVE-2026-6103","DEBIAN-CVE-2026-6103"],"status":"published","duplicateOf":null,"title":null,"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.","dates":{"published":"2026-09-25T20:08:49.333Z","modified":"2026-09-25T20:41:27.115Z","reserved":null,"kevAdded":[],"kevDue":[]},"cvss":{"headline":{"score":4.3,"severity":"medium","version":"3.1","versionLabel":"v3.1","source":"CVE.org","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","computed":false,"selection":"backend-summary"},"metrics":[{"version":"3.1","versionLabel":"v3.1","source":"CVE.org","score":4.3,"severity":"medium","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","exploitability":null,"impact":null,"computed":false},{"version":"3.1","versionLabel":"v3.1","source":"OSV · 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This occurs when an integer value is\n         incremented to a value that is too large to store in the\n         associated representation. When this occurs, the value may\n         become a very small or negative number.","type":"weakness","status":"Stable","abstraction":"Base","likelihoodOfExploit":"Medium","url":"https://cwe.mitre.org/data/definitions/190.html"}],"affected":[{"vendor":"debian","product":"php8.2","name":"php8.2","label":"php8.2","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/php8.2","purlType":"deb","versions":[{"text":"< 8.2.34-1~deb12u1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 8.2.34-1~deb12u1","eol":null,"hubHref":null},{"vendor":"debian","product":"php8.4","name":"php8.4","label":"php8.4","ecosystem":"Debian","cpePart":null,"purl":"pkg:deb/debian/php8.4","purlType":"deb","versions":[{"text":"< 8.4.26-1~deb13u1","noFixRecorded":false,"fixedIn":null},{"text":"< 8.4.26-1","noFixRecorded":false,"fixedIn":null}],"versionsText":"< 8.4.26-1~deb13u1 | < 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recorded)","eol":null,"hubHref":null},{"vendor":"ubuntu","product":"php8.5","name":"php8.5","label":"php8.5","ecosystem":"Ubuntu","cpePart":null,"purl":"pkg:deb/ubuntu/php8.5","purlType":"deb","versions":[{"text":"All versions","noFixRecorded":true,"fixedIn":null}],"versionsText":"All versions (No fix recorded)","eol":null,"hubHref":null},{"vendor":"php_group","product":"php","name":"PHP","label":"php","ecosystem":null,"cpePart":"a","purl":null,"purlType":null,"versions":[{"text":"≥ 8.2.*, < 8.2.34","noFixRecorded":false,"fixedIn":null},{"text":"≥ 8.3.*, < 8.3.35","noFixRecorded":false,"fixedIn":null},{"text":"≥ 8.4.*, < 8.4.26","noFixRecorded":false,"fixedIn":null},{"text":"≥ 8.5.*, < 8.5.11","noFixRecorded":false,"fixedIn":null}],"versionsText":"≥ 8.2.*, < 8.2.34 | ≥ 8.3.*, < 8.3.35 | ≥ 8.4.*, < 8.4.26 | ≥ 8.5.*, < 8.5.11","eol":null,"hubHref":"/vendor/php_group/php"}],"affectedCount":10,"eol":{"hasEol":false,"count":0},"references":[{"url":"https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85","label":"github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85","hostname":"github.com","tags":["Vendor Advisory","REPORT"]},{"url":"https://ubuntu.com/security/CVE-2026-6103","label":"ubuntu.com/security/CVE-2026-6103","hostname":"ubuntu.com","tags":["REPORT"]},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-6103","label":"www.cve.org/CVERecord?id=CVE-2026-6103","hostname":"www.cve.org","tags":["REPORT"]},{"url":"https://github.com/php/php-src/blob/php-8.4.26/NEWS","label":"github.com/php/php-src/blob/php-8.4.26/NEWS","hostname":"github.com","tags":["REPORT"]},{"url":"https://security-tracker.debian.org/tracker/CVE-2026-6103","label":"security-tracker.debian.org/tracker/CVE-2026-6103","hostname":"security-tracker.debian.org","tags":["Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-6103","label":"nvd.nist.gov/vuln/detail/CVE-2026-6103","hostname":"nvd.nist.gov","tags":["Oval","Advisory"]}],"lineage":{"upstream":[],"downstream":["MGASA-2026-0458","OPENSUSE-SU-2026:11901-1","OPENSUSE-SU-2026:22045-1","RHSA-2026:70720","SUSE-SU-2026:24158-1","SUSE-SU-2026:4602-1","SUSE-SU-2026:4603-1","SUSE-SU-2026:4651-1","USN-8936-1"],"duplicates":[],"related":["OPENSUSE-SU-2026:11901-1","OPENSUSE-SU-2026:22045-1","SUSE-SU-2026:24158-1","SUSE-SU-2026:4602-1","SUSE-SU-2026:4603-1","SUSE-SU-2026:4651-1"]},"timeline":[{"kind":"published","date":"2026-09-25T20:08:49.333Z","label":"Published","detail":"Vulnerability 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