Phar TAR phar_tar_number() Integer Overflow - Archive Entry Injection
Summary
| CVE | CVE-2026-6103 |
|---|---|
| State | PUBLISHED |
| Assigner | php |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-25 21:17:23 UTC |
| Updated | 2026-09-25 21:17:23 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 4.3 MEDIUM from [email protected]
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Problem Types: CWE-190 | CWE-190 CWE-190 Integer overflow or wraparound
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 4.3 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N |
| 3.1 | CNA | CVSS | 4.3 | MEDIUM | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N |
CVSS v3.1 Breakdown
Attack Vector
LocalAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
NoneIntegrity
LowAvailability
NoneCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Vendor Declared Affected Products
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/php/php-src/security/advisories/GHSA-j3wh-g957-2m85 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: @arnoldasr (GitHub) (en)
CNA: @Oblivionsage (GitHub) (en)
CNA: @OSTIF-Derek (GitHub) (en)
CNA: Jakub Zelenka (en)
CNA: Weilin Du (en)
There are currently no legacy QID mappings associated with this CVE.