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CVE-2025-14178VulnerabilityPublished Updated

CVE-2025-14178: PHP · Out-of-bounds Write

Affects PHPSource CVE Database V5

0

Not known to be exploited · CVSS 6.5 Medium · fixed in 8.5.1 : update PHP when convenient.

Data as of 26 Oct 2026, 06:26 UTC

CVSS 3.1 base score
6.5Medium
How severe the flaw is on the 0–10 CVSS scale.
EPSS
0.4% chance of exploitation in 30 days – higher than 39% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch
Available – fixed in 8.5.1, 8.4.16, 8.3.29 +7
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 27 Dec 2025

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponised: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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 2026-10-26.

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

ProductAffectedFixed in
Phpphp/phppkg:deb/php/phpOther threatsAffected
  • <8.1.34
  • <8.2.30
  • <8.3.29
  • <8.4.16
  • <8.5.1
Fixed in
  • 8.1.34
  • 8.2.30
  • 8.3.29
  • 8.4.16
  • 8.5.1
GitHubphp/php-srcpkg:github/php/php-srcOther threatsAffected
  • >=8.1.0 <8.2.0
  • >=8.2.0 <8.3.0
  • >=8.3.0 <8.4.0
  • >=8.4.0 <8.5.0
  • >=8.5.0 <8.6.0
Fixed in
  • 8.2.0
  • 8.3.0
  • 8.4.0
  • 8.5.0
  • 8.6.0

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

1. 2. In the interim, audit and limit the use of array_merge() with large or untrusted input arrays, especially those that could exceed 32-bit element counts or HT_MAX_SIZE. 3. Implement input validation and size checks on arrays before merging to prevent triggering the integer overflow condition. 4. Monitor application logs and system metrics for signs of memory corruption, crashes, or abnormal terminations related to PHP processes. 5. Employ web application firewalls (WAFs) with rules to detect and block suspicious payloads that attempt to exploit large array merges. 6. Conduct code reviews and security testing focusing on array handling in PHP applications. 7. Maintain an incident response plan to quickly address potential denial of service incidents. 8. Keep PHP and all dependencies regularly updated to minimize exposure to known vulnerabilities.

Description

In PHP versions:8.1.* before 8.1.34, 8.2.* before 8.2.30, 8.3.* before 8.3.29, 8.4.* before 8.4.16, 8.5.* before 8.5.1, a heap buffer overflow occurs in array_merge() when the total element count of packed arrays exceeds 32-bit limits or HT_MAX_SIZE, due to an integer overflow in the precomputation of element counts using zend_hash_num_elements(). This may lead to memory corruption or crashes and affect the integrity and availability of the target server.

References

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