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.

CVSS v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.5 / Impact : 1.4

Attack Vector LOCAL

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope CHANGED

References

Link	Resource
https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85	Vendor Advisory Exploit
https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85	Vendor Advisory Exploit

Configurations

Configuration 1 (hide)

OR	cpe:2.3:a:php:php::::::::
	cpe:2.3:a:php:php::::::::
	cpe:2.3:a:php:php::::::::
	cpe:2.3:a:php:php::::::::

History

23 Oct 2026, 14:07

Type	Values Removed	Values Added
First Time		Php php Php
References	~~() https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85 -~~	() https://github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85 - Vendor Advisory, Exploit
CPE		cpe:2.3:a:php:php::::::::

25 Sep 2026, 21:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-09-25 21:17

Updated : 2026-10-23 14:07

NVD link : CVE-2026-6103

Mitre link : CVE-2026-6103

CVE.ORG link : CVE-2026-6103

JSON object : View

Products Affected

php

php

CWE

CWE-190

Integer Overflow or Wraparound

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