NULL pointer dereference in PHP
CVE-2026-7259
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().
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H.
EPSS exploit prediction
EPSS: 0.003 (25.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 25.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.002 · newest: 0.003 · change: +0.001
Affected products
Weakness classification (CWE)
References
- github.com/php/php-src/security/advisories/GHSA-wm6j-2649-pv75 (vendor-advisory, Vendor Advisory)
Frequently asked questions
- What is CVE-2026-7259?
- CVE-2026-7259 is a medium-severity vulnerability in PHP, classified under NULL Pointer Dereference. CVSS score: 6.5/10. Published 2026-05-10.
- How severe is CVE-2026-7259?
- Medium severity. CVSS v3 base score is 6.5 out of 10.