CVE-2026-6103: PHP · Integer Overflow or Wraparound
Affects PHPSource CVE Database V5
Not known to be exploited · CVSS 4.3 Medium · fixed in 8.5.11 : update PHP when convenient.
Data as of 8 Nov 2026, 23:24 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 8.5.11, 8.4.26, 8.3.35 +1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 25 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 8 Nov 2026.
What to do
Upgrade PHP to 8.5.11, 8.4.26, 8.3.35 or 8.2.34.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| PHP GroupPHP | Affected
| Fixed in
|
| PHP GroupPHP | Affected
| Fixed in
|
| PHP GroupPHP | Affected
| Fixed in
|
| PHP GroupPHP | Affected
| Fixed in
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AI-suggested
If you cannot patch yet, avoid processing untrusted Phar archives or use alternative archive handling methods that do not rely on the vulnerable parsing function.
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.