CVE-2026-7259
MediumCVSS 6.5Exploitation Probability (EPSS)
Low risk10th percentile - higher than 10% of all known CVEs
Summary
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 and denial of service. Exploitable when user input influences the encoding passed to mb_regex_encoding().
Risk Assessment
An attacker can crash the PHP application (segfault), causing service disruption.
Recommendation
Update PHP to version 8.2.31, 8.3.31, 8.4.21, or 8.5.6 depending on the branch used.
Original NVD description (English source)
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().

