CVE-2026-7259 PUBLISHED

Null pointer dereference in php_mb_check_encoding() via mb_ereg_search_init()

Assigner: php
Reserved: 28.04.2026 Published: 10.05.2026 Updated: 10.05.2026

In PHP versions 8.2. before 8.2.31, 8.3. before 8.3.31, 8.4. before 8.4.21, and 8.5. before 8.5.6, a mismatch between encoding lists in Oniguruma and mbfl leads to a NULL pointer dereference, resulting in a segmentation fault and denial of service. The vulnerability is exploitable when user-controlled input can influence the encoding passed to mb_regex_encoding().

Metrics

CVSS 4.0

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:A/VC:N/VI:N/VA:L/SC:N/SI:N/SA:L/AU:Y/U:Amber
CVSS Score: 2.1

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	High	Integrity	None	Integrity	None
Attack Requirements	Present	Availability	Low	Availability	Low
Privileges Required	None
User Interaction	Active

CVSS 4.0

Product Status

Vendor	PHP Group
Product	PHP
Versions	Default: affected affected from 8.2.* to 8.2.31 (excl.) affected from 8.3.* to 8.3.31 (excl.) affected from 8.4.* to 8.4.21 (excl.) affected from 8.5.* to 8.5.6 (excl.)

Credits

Viet Hoang Luu (The University of Melbourne) reporter
Amirmohammad Pasdar (The University of Melbourne) reporter
Wachiraphan Charoenwet (The University of Melbourne) reporter
Shaanan Cohney (The University of Melbourne) reporter
Toby Murray (The University of Melbourne) reporter
Van-Thuan Pham (The University of Melbourne) reporter
Ilija Tovilo remediation developer

References

https://github.com/php/php-src/security/advisories/GHSA-wm6j-2649-pv75

Problem Types

CWE-476 NULL Pointer Dereference CWE