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Fencer Vulns
medium 6.5

CVE-2026-7259 json

Null pointer dereference in php_mb_check_encoding() via mb_ereg_search_init()

published 2026-05-07 6 mo ago modified 2026-09-10 59 d ago also BIT-libphp-2026-7259 , BIT-php-2026-7259 , BIT-php-min-2026-7259 , EUVD-2026-28969 , GHSA-wm6j-2649-pv75

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 8%
public exploits
0
none known

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, 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().

Patch / fix

  • bitnami libphp 8.2.31, 8.3.31, 8.4.21, 8.5.6
  • bitnami php 8.2.31, 8.3.31, 8.4.21, 8.5.6
  • bitnami php-min 8.2.31, 8.3.31, 8.4.21, 8.5.6
  • PHP Group PHP 8.2.31, 8.3.31, 8.4.21, 8.5.6
  • php8.2 Debian 12 8.2.31-1~deb12u1
  • php8.4 Debian 13 8.4.21-1~deb13u1
  • php8.4 Debian 14 8.4.21-1

debian advisories DEBIAN-CVE-2026-7259

  • php8.1 Ubuntu 22.04 LTS 8.1.2-1ubuntu2.24
  • php8.3 Ubuntu 24.04 LTS 8.3.6-0ubuntu0.24.04.9
  • php8.4 Ubuntu 25.10 8.4.11-1ubuntu1.2
  • php8.5 Ubuntu 26.04 LTS 8.5.4-0ubuntu1.1

ubuntu advisories UBUNTU-CVE-2026-7259

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • php RHEL 9 8.0.30-6.el9_8
  • php-gd RHEL 9 8.0.30-6.el9_8
  • php-cli RHEL 9 8.0.30-6.el9_8
  • php-dba RHEL 9 8.0.30-6.el9_8
  • php-dbg RHEL 9 8.0.30-6.el9_8
  • php-ffi RHEL 9 8.0.30-6.el9_8
  • php-fpm RHEL 9 8.0.30-6.el9_8
  • php-gmp RHEL 9 8.0.30-6.el9_8

red hat advisories RHSA-2026:33449RHSA-2026:23388

  • php8 openSUSE Tumbleweed 8.5.6-1.1

opensuse advisories openSUSE-SU-2026:10747-1

  • php AlmaLinux 9 8.0.30-6.el9_8
  • php-gd AlmaLinux 9 8.0.30-6.el9_8
  • php-cli AlmaLinux 9 8.0.30-6.el9_8
  • php-dba AlmaLinux 9 8.0.30-6.el9_8
  • php-dbg AlmaLinux 9 8.0.30-6.el9_8
  • php-ffi AlmaLinux 9 8.0.30-6.el9_8
  • php-fpm AlmaLinux 9 8.0.30-6.el9_8
  • php-gmp AlmaLinux 9 8.0.30-6.el9_8

almalinux advisories ALSA-2026:33449ALSA-2026:23388

  • php Rocky Linux 9 8.0.30-6.el9_8
  • php Rocky Linux 10 8.3.31-1.el10_2

rocky linux advisories RLSA-2026:33449RLSA-2026:23388

  • php81 Alpine 3.19 8.1.34-r0
  • php82 Alpine 3.22 8.2.31-r0
  • php83 Alpine 3.22 8.3.36-r0
  • php83 Alpine 3.24, Alpine 3.23 8.3.31-r0
  • php84 Alpine 3.22 8.4.27-r0
  • php84 Alpine 3.24, Alpine 3.23 8.4.21-r0
  • php85 Alpine 3.24, Alpine 3.23 8.5.6-r0

alpine advisories ALPINE-CVE-2026-7259

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • php Azure Linux 3.0 8.3.31-1

azure linux advisories AZL-86364

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-7259 updated cvss 6.5

php: NULL pointer dereference in php_mb_check_encoding() via mb_ereg_search_init()

  • Red Hat Enterprise Linux 8 php, libzip, php-gd, php-cli, php-dba, php-dbg, +30 more Red Hat Enterprise Linux 9 php, php-gd, php-cli, php-dba, php-dbg, php-ffi, +18 more Red Hat Enterprise Linux 10 php8.4
    affected: workaround, no fix available “Fix deferred”
  • Red Hat Enterprise Linux AppStream (v. 9) php 8.0.30-6.el9_8, php-gd 8.0.30-6.el9_8, php-cli 8.0.30-6.el9_8, php-dba 8.0.30-6.el9_8, php-dbg 8.0.30-6.el9_8, php-ffi 8.0.30-6.el9_8, +18 more
    fixed: vendor fix RHSA-2026:33449
  • Red Hat Enterprise Linux AppStream (v. 10) php 8.3.31-1.el10_2, php-gd 8.3.31-1.el10_2, php-cli 8.3.31-1.el10_2, php-dba 8.3.31-1.el10_2, php-dbg 8.3.31-1.el10_2, php-ffi 8.3.31-1.el10_2, +18 more
    fixed: vendor fix RHSA-2026:23388
  • Red Hat Enterprise Linux 6 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +20 more Red Hat Enterprise Linux 7 php, php-gd, php-cli, php-dba, php-fpm, php-pdo, +18 more Red Hat Enterprise Linux 8 php, libzip, php-gd, php-cli, php-dba, php-dbg, +30 more Red Hat Hardened Images php
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5 mo ago

Exploit prediction

0.19% chance of exploitation in the next 30 days, higher than 8% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 2.1 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
CNA 4.0 2.1 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
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
OSV 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
bitnami libphp
>=8.2.0, <8.2.31
>=8.3.0, <8.3.31
>=8.4.0, <8.4.21
>=8.5.0, <8.5.6
8.2.31
8.3.31
8.4.21
8.5.6
bitnami php
>=8.2.0, <8.2.31
>=8.3.0, <8.3.31
>=8.4.0, <8.4.21
>=8.5.0, <8.5.6
8.2.31
8.3.31
8.4.21
8.5.6
bitnami php-min
>=8.2.0, <8.2.31
>=8.3.0, <8.3.31
>=8.4.0, <8.4.21
>=8.5.0, <8.5.6
8.2.31
8.3.31
8.4.21
8.5.6

Affected products

  • PHP Group PHP

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

The maintainers of php/php-src published their own advisory on GitHub. Reviewed sources take precedence over it.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.