Description
The IPv6 branch of the FastCGI client access check compares only the first 12 bytes of a 16-byte IPv6 address, so listen.allowed_clients matches on a /96 prefix instead of the exact address. An attacker who can source an address sharing the first 96 bits with an allowed one passes the check and reaches the FastCGI endpoint.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| PHP Group | PHP | 8.2.* – < 8.2.34, 8.3.* – < 8.3.35, 8.4.* – < 8.4.26, 8.5.* – < 8.5.11 | 8.2.34 |
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 | 8.4.26-1 | — |
| Debian 13 | php8.4 | 8.4.26-1~deb13u1 | — |
| Debian 12 | php8.2 | 8.2.34-1~deb12u1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | php8.5 | 8.5.9-0ubuntu2 | USN-8936-1 |
| Ubuntu 26.04 LTS | php8.5 | 8.5.4-0ubuntu1.4 | USN-8936-1 |
| Ubuntu 24.04 LTS | php8.3 | 8.3.6-0ubuntu0.24.04.12 | USN-8936-1 |
| Ubuntu 22.04 LTS | php8.1 | 8.1.2-1ubuntu2.27 | USN-8936-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | php7.4 | 7.4.3-4ubuntu2.29+esm4 | USN-8936-1 |
| Ubuntu Pro 18.04 LTS | php7.2 | 7.2.24-0ubuntu0.18.04.17+esm13 | USN-8936-1 |
| Ubuntu Pro 16.04 LTS | php7.0 | 7.0.33-0ubuntu0.16.04.16+esm21 | USN-8936-1 |
| Ubuntu Pro 14.04 LTS | php5 | 5.5.9+dfsg-1ubuntu4.29+esm17 | USN-8936-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | php +26 | 8.5.11-2.hum1 | RHSA-2026:70720 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | apcu-panel +2 | 5.1.18-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux 8 | libzip +1 | 1.6.1-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux 8 | libzip-tools | 1.6.1-1.module_el8.6.0+3239+bedf0508 | ALSA-2026:87080 |
| AlmaLinux 8 | php +25 | 7.4.33-8.module_el8.10.0+4321+cf5fd4bb | ALSA-2026:87080 |
| AlmaLinux 8 | php-pear | 1:1.10.13-1.module_el8.10.0+3935+28808425 | ALSA-2026:87080 |
| AlmaLinux 8 | php-pecl-rrd | 2.0.1-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux 8 | php-pecl-xdebug | 2.9.5-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
| AlmaLinux 8 | php-pecl-zip | 1.18.2-1.module_el8.6.0+2750+78feabcb | ALSA-2026:87080 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 8 | libzip | 1.6.1-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux 8 | php | 7.4.33-8.module+el8.10.0+40393+c071e357 | RLSA-2026:87080 |
| Rocky Linux 8 | php-pear | 1:1.10.13-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux 8 | php-pecl-apcu | 5.1.18-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux 8 | php-pecl-rrd | 2.0.1-1.module+el8.4.0+414+2e7afcdd | RLSA-2026:87080 |
| Rocky Linux 8 | php-pecl-xdebug | 2.9.5-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
| Rocky Linux 8 | php-pecl-zip | 1.18.2-1.module+el8.10.0+1604+6558efc7 | RLSA-2026:87080 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | php7 +4 | 7.4.33-150400.4.81.1 | SUSE-SU-2026:4853-1 |
| SLES 15 SP7 | php7-test | 7.4.33-150400.4.81.2 | SUSE-SU-2026:4853-1 |
| SLES 15 SP7 | php8 +5 | 8.3.35-150700.3.21.1 | SUSE-SU-2026:4602-1 |
| SLES 15 SP6 | php7 +3 | 7.4.33-150400.4.81.1 | SUSE-SU-2026:4853-1 |
| SLES 15 SP6 | php8 +5 | 8.2.34-150600.3.36.1 | SUSE-SU-2026:4603-1 |
| SLES 15 SP5 | php7 +3 | 7.4.33-150400.4.81.1 | SUSE-SU-2026:4853-1 |
| SLES 15 SP5 | php8 +4 | 8.0.30-150400.4.76.1 | SUSE-SU-2026:4651-1 |
| SLES 15 SP5 | php8-test | 8.0.30-150400.4.76.2 | SUSE-SU-2026:4651-1 |
| SLES 15 SP4 | php7 +3 | 7.4.33-150400.4.81.1 | SUSE-SU-2026:4853-1 |
| SLES 15 SP4 | php8 +4 | 8.0.30-150400.4.76.1 | SUSE-SU-2026:4651-1 |
| SLES 15 SP4 | php8-test | 8.0.30-150400.4.76.2 | SUSE-SU-2026:4651-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | php8 +4 | 8.4.26-160000.1.1 | SUSE-SU-2026:24158-1 |
| SLES for SAP 15 SP6 | php7 +3 | 7.4.33-150400.4.81.1 | SUSE-SU-2026:4853-1 |
| SLES for SAP 15 SP6 | php8 +5 | 8.2.34-150600.3.36.1 | SUSE-SU-2026:4603-1 |
| SLES for SAP 15 SP5 | php7 +3 | 7.4.33-150400.4.81.1 | SUSE-SU-2026:4853-1 |
| SLES for SAP 15 SP5 | php8 +4 | 8.0.30-150400.4.76.1 | SUSE-SU-2026:4651-1 |
| SLES for SAP 15 SP5 | php8-test | 8.0.30-150400.4.76.2 | SUSE-SU-2026:4651-1 |
| SLES for SAP 15 SP4 | php7 +3 | 7.4.33-150400.4.81.1 | SUSE-SU-2026:4853-1 |
| SLES for SAP 15 SP4 | php8 +4 | 8.0.30-150400.4.76.1 | SUSE-SU-2026:4651-1 |
| SLES for SAP 15 SP4 | php8-test | 8.0.30-150400.4.76.2 | SUSE-SU-2026:4651-1 |
| SLES 16.0 | php8 +4 | 8.4.26-160000.1.1 | SUSE-SU-2026:24158-1 |
| SLE HPC 15 SP5 | php8 +4 | 8.0.30-150400.4.76.1 | SUSE-SU-2026:4651-1 |
| SLE HPC 15 SP5 | php8-test | 8.0.30-150400.4.76.2 | SUSE-SU-2026:4651-1 |
| SLE HPC 15 SP4 | php7 +3 | 7.4.33-150400.4.81.1 | SUSE-SU-2026:4853-1 |
| SLE HPC 15 SP4 | php8 +4 | 8.0.30-150400.4.76.1 | SUSE-SU-2026:4651-1 |
| SLE HPC 15 SP4 | php8-test | 8.0.30-150400.4.76.2 | SUSE-SU-2026:4651-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | php8 | 8.5.11-1.1 | openSUSE-SU-2026:11901-1 |
| openSUSE Leap 16.0 | php8 +5 | 8.4.26-160000.1.1 | openSUSE-SU-2026:22045-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | php83 | 8.3.35-r0 | — |
| Alpine v3.24 | php84 | 8.4.26-r0 | — |
| Alpine v3.24 | php85 | 8.5.11-r0 | — |
| Alpine v3.23 | php83 | 8.3.36-r0 | — |
| Alpine v3.23 | php84 | 8.4.27-r0 | — |
| Alpine v3.23 | php85 | 8.5.12-r0 | — |
| Alpine v3.22 | php82 | 8.2.35-r0 | — |
| Alpine v3.22 | php83 | 8.3.36-r0 | — |
| Alpine v3.22 | php84 | 8.4.27-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | php8.2 +27 | 8.2.34-1.amzn2023.0.1 | ALAS2023-2026-3161 |
| Amazon Linux 2023 | php8.3 +28 | 8.3.35-1.amzn2023.0.1 | ALAS2023-2026-3162 |
| Amazon Linux 2023 | php8.4 +27 | 8.4.26-1.amzn2023.0.1 | ALAS2023-2026-3163 |
| Amazon Linux 2023 | php8.5 +26 | 8.5.11-1.amzn2023.0.1 | ALAS2023-2026-3164 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | php | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | apcu-panel +2 | 5.1.18-1.module+el8.10.0+90472+f810484b | ELSA-2026-87080 |
| Oracle Linux 8 | libzip +2 | 1.6.1-1.module+el8.10.0+90472+f810484b | ELSA-2026-87080 |
| Oracle Linux 8 | php +25 | 7.4.33-8.module+el8.10.0+91080+9785160d | ELSA-2026-87080 |
| Oracle Linux 8 | php-pear | 1:1.10.13-1.module+el8.10.0+90472+f810484b | ELSA-2026-87080 |
| Oracle Linux 8 | php-pecl-rrd | 2.0.1-1.module+el8.10.0+90472+f810484b | ELSA-2026-87080 |
| Oracle Linux 8 | php-pecl-xdebug | 2.9.5-1.module+el8.10.0+90472+f810484b | ELSA-2026-87080 |
| Oracle Linux 8 | php-pecl-zip | 1.18.2-1.module+el8.10.0+90472+f810484b | ELSA-2026-87080 |
Advisories 16
- ALSA-2026:87080 Important: php:7.4 security update AlmaLinux Security Advisories · Oct 29, 2026
- USN-8936-1 php8.5, php8.3, php8.1, php7.4, php7.2, php7.0, php5 vulnerabilities Ubuntu Security Notices (USN) · Oct 28, 2026
- SUSE-SU-2026:4853-1 Security update for php7 SUSE / openSUSE Security Updates · Oct 22, 2026
- RLSA-2026:87080 Important: php:7.4 security update Rocky Linux Security Advisories · Oct 22, 2026
- ELSA-2026-87080 Important: php:7.4 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Oct 21, 2026
- openSUSE-SU-2026:22045-1 Security update for php8 SUSE / openSUSE Security Updates · Oct 19, 2026
- SUSE-SU-2026:24158-1 Security update for php8 SUSE / openSUSE Security Updates · Oct 16, 2026
- RHSA-2026:70720 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- SUSE-SU-2026:4651-1 Security update for php8 SUSE / openSUSE Security Updates · Oct 14, 2026
- ALAS2023-2026-3161 Important: php8.2 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 12, 2026
- ALAS2023-2026-3162 Important: php8.3 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 12, 2026
- ALAS2023-2026-3163 Important: php8.4 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 12, 2026
- ALAS2023-2026-3164 Important: php8.5 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 12, 2026
- SUSE-SU-2026:4602-1 Security update for php8 SUSE / openSUSE Security Updates · Oct 9, 2026
- SUSE-SU-2026:4603-1 Security update for php8 SUSE / openSUSE Security Updates · Oct 9, 2026
- openSUSE-SU-2026:11901-1 php8-8.5.11-1.1 on GA media SUSE / openSUSE Security Updates · Sep 29, 2026