Description
Improper Neutralization of Escape, Meta, or Control Sequences vulnerability in Apache HTTP Server through environment variables set via the Apache configuration unexpectedly superseding variables calculated by the server for CGI programs.
This issue affects Apache HTTP Server from 2.4.0 through 2.4.65.
Users are recommended to upgrade to version 2.4.66 which fixes the issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.0 – ≤ 2.4.65 | — |
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 | apache2 | 2.4.66-1 | — |
| Debian 13 | apache2 | 2.4.66-1~deb13u1 | — |
| Debian 12 | apache2 | 2.4.66-1~deb12u1 | — |
| Debian 11 | apache2 | 2.4.66-1~deb11u1 | DLA-4452-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | apache2 | 2.4.66-2ubuntu1 | — |
| Ubuntu 25.10 | apache2 | 2.4.64-1ubuntu3.2 | USN-7968-1 |
| Ubuntu 24.04 LTS | apache2 | 2.4.58-1ubuntu8.10 | USN-7968-1 |
| Ubuntu 22.04 LTS | apache2 | 2.4.52-1ubuntu4.18 | USN-7968-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 20.04 LTS | apache2 | 2.4.41-4ubuntu3.23+esm3 | USN-8338-1 |
| Ubuntu Pro 18.04 LTS | apache2 | 2.4.29-1ubuntu4.27+esm7 | USN-8338-1 |
| Ubuntu Pro 16.04 LTS | apache2 | 2.4.18-2ubuntu3.17+esm17 | USN-8338-1 |
| Ubuntu Pro 14.04 LTS | apache2 | 2.4.7-1ubuntu4.22+esm12 | USN-8338-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | httpd +8 | 2.4.63-4.el10_1.3 | RHSA-2025:23932 |
| RHEL 10 | mod_ssl +1 | 1:2.4.63-4.el10_1.3 | RHSA-2025:23932 |
| RHEL 9 | httpd +8 | 2.4.62-7.el9_7.3 | RHSA-2025:23919 |
| RHEL 9 | mod_ssl +1 | 1:2.4.62-7.el9_7.3 | RHSA-2025:23919 |
| RHEL 8 | httpd +6 | 2.4.37-65.module+el8.10.0+23815+1b5e1c66.7 | RHSA-2025:23732 |
| RHEL 8 | mod_http2 | 1.15.7-10.module+el8.10.0+23369+11a81384.4 | RHSA-2025:23732 |
| RHEL 8 | mod_md | 1:2.0.8-8.module+el8.10.0+23815+1b5e1c66.2 | RHSA-2025:23732 |
| RHEL 8 | mod_ssl +1 | 1:2.4.37-65.module+el8.10.0+23815+1b5e1c66.7 | RHSA-2025:23732 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat JBoss Core Services 1 | jbcs-httpd24-apr-util +8 | 1.6.3-4.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-curl +2 | 8.11.0-4.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-httpd +6 | 2.4.62-11.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_http2 | 2.0.29-8.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_jk +1 | 1.2.50-12.redhat_1.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_md | 1:2.4.28-13.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_proxy_cluster | 1.3.22-7.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_security | 2.9.6-14.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-mod_ssl +1 | 1:2.4.62-11.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-openssl +4 | 1:1.1.1k-21.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-openssl-chil | 1.0.0-25.el7jbcs | RHSA-2026:2994 |
| Red Hat JBoss Core Services 1 | jbcs-httpd24-openssl-pkcs11 | 0.4.12-5.el7jbcs | RHSA-2026:2994 |
| Red Hat Hardened Images 1 | httpd +5 | 2.4.66-6.hum1 | RHSA-2026:5156 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | httpd-filesystem | 2.4.63-4.el10_1.3 | ALSA-2025:23932 |
| AlmaLinux 9 | httpd +8 | 2.4.62-7.el9_7.3 | ALSA-2025:23919 |
| AlmaLinux 9 | mod_ssl +1 | 1:2.4.62-7.el9_7.3 | ALSA-2025:23919 |
| AlmaLinux 8 | httpd +6 | 2.4.37-65.module_el8.10.0+4088+57f011c1.7 | ALSA-2025:23732 |
| AlmaLinux 8 | mod_http2 | 1.15.7-10.module_el8.10.0+4044+ea5f78b1.4 | ALSA-2025:23732 |
| AlmaLinux 8 | mod_md | 1:2.0.8-8.module_el8.10.0+4088+57f011c1.2 | ALSA-2025:23732 |
| AlmaLinux 8 | mod_ssl +1 | 1:2.4.37-65.module_el8.10.0+4088+57f011c1.7 | ALSA-2025:23732 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | httpd | 2.4.63-4.el10_1.3 | RLSA-2025:23932 |
| Rocky Linux 9 | httpd | 2.4.62-7.el9_7.3 | RLSA-2025:23919 |
| Rocky Linux 8 | httpd | 2.4.37-65.module+el8.10.0+1830+22f0c9e0 | RLSA-2025:23732 |
| Rocky Linux 8 | mod_http2 | 1.15.7-10.module+el8.10.0+1775+6b057638 | RLSA-2025:23732 |
| Rocky Linux 8 | mod_md | 1:2.0.8-8.module+el8.9.0+1370+89cc8ad5 | RLSA-2025:23732 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:0019-1, SUSE-SU-2025:4518-1 |
| SLES 15 SP7 | apache2-devel +4 | 2.4.62-150700.4.9.1 | SUSE-SU-2025:4518-1 |
| SLES 15 SP6 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:0020-1, SUSE-SU-2026:0019-1 |
| SLES 15 SP6 | apache2-devel +3 | 2.4.58-150600.5.41.1 | SUSE-SU-2026:0020-1 |
| SLES 15 SP5 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:2686-1, SUSE-SU-2026:0019-1 |
| SLES 15 SP4 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:2686-1, SUSE-SU-2026:0019-1 |
| SLES 12 SP5 | apache2 +1 | 2.4.51-35.75.1 | SUSE-SU-2025:4488-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | apache2 +6 | 2.4.63-160000.3.1 | SUSE-SU-2026:20081-1 |
| SLES for SAP 15 SP6 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:0020-1, SUSE-SU-2026:0019-1 |
| SLES for SAP 15 SP6 | apache2-devel +3 | 2.4.58-150600.5.41.1 | SUSE-SU-2026:0020-1 |
| SLES for SAP 15 SP5 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:2686-1, SUSE-SU-2026:0019-1 |
| SLES for SAP 15 SP4 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:2686-1, SUSE-SU-2026:0019-1 |
| SLES 16.0 | apache2 +6 | 2.4.63-160000.3.1 | SUSE-SU-2026:20081-1 |
| SLE HPC 15 SP5 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:2686-1, SUSE-SU-2026:0019-1 |
| SLE HPC 15 SP4 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:2686-1, SUSE-SU-2026:0019-1 |
| SUSE Manager Server LTS 4.3 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:0019-1 |
| SUSE Manager Proxy LTS 4.3 | apache2 | 2.4.51-150400.6.52.1 | SUSE-SU-2026:0019-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | apache2 | 2.4.66-1.1 | openSUSE-SU-2025:15808-1 |
| openSUSE Leap 16.0 | apache2 +6 | 2.4.63-160000.3.1 | openSUSE-SU-2026:20030-1 |
| openSUSE Leap 15.6 | apache2 +6 | 2.4.58-150600.5.41.1 | SUSE-SU-2026:0020-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | apache2 | 2.4.66-r0 | — |
| Alpine v3.23 | apache2 | 2.4.66-r0 | — |
| Alpine v3.22 | apache2 | 2.4.66-r0 | — |
| Alpine v3.21 | apache2 | 2.4.66-r0 | — |
| Alpine v3.20 | apache2 | 2.4.66-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | httpd +8 | 2.4.66-1.amzn2023.0.1 | ALAS2023-2025-1318 |
| Amazon Linux 2023 | mod_ssl +1 | 1:2.4.66-1.amzn2023.0.1 | ALAS2023-2025-1318 |
| Amazon Linux 2 | httpd +7 | 2.4.66-1.amzn2.0.1 | ALAS2-2025-3099 |
| Amazon Linux 2 | mod_ssl +1 | 1:2.4.66-1.amzn2.0.1 | ALAS2-2025-3099 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | httpd | 2.4.66-1 | — |
| Azure Linux 2 (CBL-Mariner) | httpd | 2.4.66-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | httpd +8 | 2.4.63-4.0.1.el10_1.3 | ELSA-2025-23932 |
| Oracle Linux 10 | mod_ssl +1 | 1:2.4.63-4.0.1.el10_1.3 | ELSA-2025-23932 |
| Oracle Linux 9 | httpd +8 | 2.4.62-7.0.1.el9_7.3 | ELSA-2025-23919 |
| Oracle Linux 9 | mod_ssl +1 | 1:2.4.62-7.0.1.el9_7.3 | ELSA-2025-23919 |
| Oracle Linux 8 | httpd +6 | 2.4.37-65.0.1.module+el8.10.0+90740+3332f30e.7 | ELSA-2025-23732 |
| Oracle Linux 8 | mod_http2 | 1.15.7-10.module+el8.10.0+90652+bef864ba.4 | ELSA-2025-23732 |
| Oracle Linux 8 | mod_md | 1:2.0.8-8.module+el8.10.0+90740+3332f30e.2 | ELSA-2025-23732 |
| Oracle Linux 8 | mod_ssl +1 | 1:2.4.37-65.0.1.module+el8.10.0+90740+3332f30e.7 | ELSA-2025-23732 |
Advisories 36
- WID-SEC-2026-2189 Dell PowerProtect Data Domain: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 2, 2026
- WID-SEC-2025-2750 Apache HTTP Server: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 1, 2026
- ALSA-2025:23919 Important: httpd security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:23932 Important: httpd security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2025:23732 Important: httpd:2.4 security update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2026:2994 Red Hat Security Advisory: Red Hat JBoss Core Services Apache HTTP Server 2.4.62 SP3 security update Red Hat Security Advisories (RHSA) · Oct 17, 2026
- RHSA-2026:5156 Red Hat Security Advisory: Red Hat Hardened Images RPM Release Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2025:23932 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2025:23919 Red Hat Security Advisory: httpd security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- RHSA-2025:23732 Red Hat Security Advisory: httpd:2.4 security update Red Hat Security Advisories (RHSA) · Oct 16, 2026
- WID-SEC-2026-0349 Dell Avamar und NetWorker: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 17, 2026
- WID-SEC-2026-0853 Apple macOS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Sep 8, 2026
- WID-SEC-2026-1730 Xerox FreeFlow Print Server: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Jul 16, 2026
- SUSE-SU-2026:2686-1 Security update for apache2 SUSE / openSUSE Security Updates · Jul 1, 2026
- USN-8338-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · May 29, 2026
- USN-7968-1 apache2 vulnerabilities Ubuntu Security Notices (USN) · Apr 27, 2026
- WID-SEC-2026-1203 Oracle Fusion Middleware: Mehrere Schwachstellen BSI CERT-Bund (WID) · Apr 21, 2026
- NCSC-2026-0102 Kwetsbaarheden verholpen in Apple macOS NCSC-NL (Netherlands) · Mar 25, 2026
- openSUSE-SU-2026:20030-1 Security update for apache2 SUSE / openSUSE Security Updates · Mar 23, 2026
- openSUSE-SU-2025:15808-1 apache2-2.4.66-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20081-1 Security update for apache2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0019-1 Security update for apache2 SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0020-1 Security update for apache2 SUSE / openSUSE Security Updates · Mar 23, 2026
- DLA-4452-1 apache2 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2025:4518-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2025:4488-1 Security update for apache2 SUSE / openSUSE Security Updates · Feb 4, 2026
- NCSC-2026-0021 Kwetsbaarheden verholpen in Oracle Database Server producten NCSC-NL (Netherlands) · Jan 21, 2026
- WID-SEC-2026-0155 Oracle Secure Backup: Schwachstelle gefährdet Vertraulichkeit und Integrität BSI CERT-Bund (WID) · Jan 20, 2026
- ALAS2023-2025-1318 Important: httpd security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Jan 7, 2026
- ALAS2-2025-3099 Important: httpd security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Jan 5, 2026
- RLSA-2025:23932 Important: httpd security update Rocky Linux Security Advisories · Dec 24, 2025
- ELSA-2025-23732 Important: httpd:2.4 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Dec 24, 2025
- RLSA-2025:23919 Important: httpd security update Rocky Linux Security Advisories · Dec 23, 2025
- RLSA-2025:23732 Important: httpd:2.4 security update Rocky Linux Security Advisories · Dec 22, 2025
- ELSA-2025-23932 Important: httpd security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Dec 22, 2025
- ELSA-2025-23919 Important: httpd security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Dec 22, 2025
References
- https://httpd.apache.org/security/vulnerabilities_24.html vendor-advisory