Description
In PHP versions 8.4.* before 8.4.21 and 8.5.* before 8.5.6, DOMNode::C14N() method may process the XML data incorrectly, causing a circular linked list in the data structure representing the XML document. This may cause subsequent processing of the XML document to enter infinite loop, causing denial of service in the processing application.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| PHP Group | PHP | 8.4.* – < 8.4.21, 8.5.* – < 8.5.6 | 8.4.21 |
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 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | php8.5 | 8.5.4-0ubuntu1.1 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | php8.4 +23 | 8.4.21-1.el10_2 | RHSA-2026:22649 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | php8.4 +23 | 8.4.21-1.el10_2 | ALSA-2026:22649 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | php8.4 | 8.4.21-1.el10_2 | RLSA-2026:22649 |
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 | php85 | 8.5.6-r0 | — |
| Alpine v3.23 | php84 | 8.4.21-r0 | — |
| Alpine v3.23 | php85 | 8.5.6-r0 | — |
| Alpine v3.22 | php84 | 8.4.27-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| 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 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | php8.4 +23 | 8.4.21-1.el10_2 | ELSA-2026-22649 |
Advisories 9
- ALSA-2026:22649 Important: php8.4 security update AlmaLinux Security Advisories · Nov 6, 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-2026:22649 Red Hat Security Advisory: php8.4 security update Red Hat Security Advisories (RHSA) · Sep 22, 2026
- ELSA-2026-22649 Important: php8.4 security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 17, 2026
- ALAS2023-2026-1733 Important: php8.5 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 13, 2026
- ALAS2023-2026-1726 Important: php8.4 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jul 13, 2026
- RLSA-2026:22649 Important: php8.4 security update Rocky Linux Security Advisories · Jun 5, 2026
- openSUSE-SU-2026:10747-1 php8-8.5.6-1.1 on GA media SUSE / openSUSE Security Updates · May 12, 2026