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().
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| PHP Group | PHP | 8.2.* – < 8.2.31, 8.3.* – < 8.3.31, 8.4.* – < 8.4.21, 8.5.* – < 8.5.6 | 8.2.31 |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | php8.4 | 8.4.21-1 | — |
| Debian 13 | php8.4 | 8.4.21-1~deb13u1 | — |
| Debian 12 | php8.2 | 8.2.31-1~deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | php8.5 | 8.5.4-0ubuntu1.1 | — |
| Ubuntu 25.10 | php8.4 | 8.4.11-1ubuntu1.2 | — |
| Ubuntu 24.04 LTS | php8.3 | 8.3.6-0ubuntu0.24.04.9 | — |
| Ubuntu 22.04 LTS | php8.1 | 8.1.2-1ubuntu2.24 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | php +23 | 8.3.31-1.el10_2 | RHSA-2026:23388 |
| RHEL 9 | php +23 | 8.0.30-6.el9_8 | RHSA-2026:33449 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | php +23 | 8.3.31-1.el10_2 | ALSA-2026:23388 |
| AlmaLinux 9 | php +23 | 8.0.30-6.el9_8 | ALSA-2026:33449 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | php | 8.3.31-1.el10_2 | RLSA-2026:23388 |
| Rocky Linux 9 | php | 8.0.30-6.el9_8 | RLSA-2026:33449 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | php8 | 8.5.6-1.1 | openSUSE-SU-2026:10747-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | php83 | 8.3.31-r0 | — |
| Alpine v3.24 | php84 | 8.4.21-r0 | — |
| Alpine v3.24 | php85 | 8.5.6-r0 | — |
| Alpine v3.23 | php83 | 8.3.31-r0 | — |
| Alpine v3.23 | php84 | 8.4.21-r0 | — |
| Alpine v3.23 | php85 | 8.5.6-r0 | — |
| Alpine v3.22 | php82 | 8.2.31-r0 | — |
| Alpine v3.22 | php83 | 8.3.36-r0 | — |
| Alpine v3.22 | php84 | 8.4.27-r0 | — |
| Alpine v3.19 | php81 | 8.1.34-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | php8.2 +27 | 8.2.31-1.amzn2023.0.1 | ALAS2023-2026-1727 |
| Amazon Linux 2023 | php8.3 +28 | 8.3.31-1.amzn2023.0.1 | ALAS2023-2026-1728 |
| Amazon Linux 2023 | php8.4 +27 | 8.4.21-1.amzn2023.0.1 | ALAS2023-2026-1726 |
| Amazon Linux 2023 | php8.5 +26 | 8.5.6-1.amzn2023.0.1 | ALAS2023-2026-1733 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | php | 8.3.31-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | php +23 | 8.3.31-1.el10_2 | ELSA-2026-23388 |
| Oracle Linux 9 | php +23 | 8.0.30-6.el9_8 | ELSA-2026-33449 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | php-8.2 | 8.2.31-r0 | — |
Advisories 15
- ALSA-2026:23388 Important: php security update AlmaLinux Security Advisories · Nov 6, 2026
- ALSA-2026:33449 Important: php security update AlmaLinux Security Advisories · Oct 29, 2026
- WID-SEC-2026-2455 Oracle Solaris Drittanbieterkomponenten: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 27, 2026
- WID-SEC-2026-1433 PHP: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 21, 2026
- RHSA-2026:33449 Red Hat Security Advisory: php security update Red Hat Security Advisories (RHSA) · Sep 22, 2026
- RHSA-2026:23388 Red Hat Security Advisory: php security update Red Hat Security Advisories (RHSA) · Sep 22, 2026
- RLSA-2026:33449 Important: php security update Rocky Linux Security Advisories · Jul 29, 2026
- ELSA-2026-23388 Important: php security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 16, 2026
- ALAS2023-2026-1726 Important: php8.4 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 13, 2026
- ALAS2023-2026-1733 Important: php8.5 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 13, 2026
- ELSA-2026-33449 Important: php security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 2, 2026
- RLSA-2026:23388 Important: php security update Rocky Linux Security Advisories · Jun 6, 2026
- ALAS2023-2026-1727 Important: php8.2 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 26, 2026
- ALAS2023-2026-1728 Important: php8.3 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 26, 2026
- openSUSE-SU-2026:10747-1 php8-8.5.6-1.1 on GA media SUSE / openSUSE Security Updates · May 12, 2026