CVE-2026-7259
Null pointer dereference in php_mb_check_encoding() via mb_ereg_search_init()
6.5
MEDIUM
CVSS 3.1
EPSS 0.06%
Description
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().
How to fix CVE-2026-7259
To remediate CVE-2026-7259, upgrade the affected package to a fixed version below.
- —upgrade to 8.2.31 or later
- —upgrade to 8.2.31 or later
- —upgrade to 8.2.31 or later
- —upgrade to 8.2.31-1~deb12u1 or later
- —upgrade to 8.4.21-1~deb13u1 or later
Is CVE-2026-7259 being exploited?
Low — EPSS is 0.1%, meaning exploitation activity has not been observed at scale.
Affected packages (5)
- >= 8.2.0, < 8.2.31, >= 8.3.0, < 8.3.31, >= 8.4.0, < 8.4.21, >= 8.5.0, < 8.5.6
- >= 8.2.0, < 8.2.31, >= 8.3.0, < 8.3.31, >= 8.4.0, < 8.4.21, >= 8.5.0, < 8.5.6
- >= 8.2.0, < 8.2.31, >= 8.3.0, < 8.3.31, >= 8.4.0, < 8.4.21, >= 8.5.0, < 8.5.6
- from 0, < 8.2.31-1~deb12u1
- from 0, < 8.4.21-1~deb13u1
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 4.0 | — | 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:X/V:X/RE:X/U:Amber |
| osv | CVSS 3.1 | MEDIUM6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H |