Vulnerability · Published Oct 1, 2026 · Assigned by apache
CVE-2026-73637Apache HTTP Server: mod_auth_digest DoS attack
High 7.3
In plain English
A high-severity use-after-free in Apache HTTP Server from Apache Software Foundation. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)7.3High
Exploit odds (30 days)0.5%top 59.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
Use after free in mod_auth_digest in Apache Software Foundation Apache HTTP Server before 2.4.69 on all platforms allows an unauthenticated remote client to cause authentication state corruption via concurrent Digest authentication requests when AuthDigestNcCheck is enabled or AuthDigestNonceLifetime is set to 0. Users are recommended to upgrade to version 2.4.69, which fixes this issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux:10 | httpd | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | httpd | 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | httpd | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:10 | httpd-core | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:9 | httpd-core | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:10 | httpd-devel | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | httpd-devel | 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | httpd-devel | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:10 | httpd-filesystem | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | httpd-filesystem | 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | httpd-filesystem | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:10 | httpd-manual | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | httpd-manual | 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | httpd-manual | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:10 | httpd-tools | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | httpd-tools | 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | httpd-tools | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:8 | mod_http2 | 1.15.7-10.module_el8.10.0+4233+8b7d9181.7 | ALSA-2026:92616 |
| AlmaLinux:8 | mod_http2 | 1.15.7-10.module_el8.10.0+4270+e5f13fdb.7 | ALSA-2026:92616 |
| AlmaLinux:10 | mod_ldap | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | mod_ldap | 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | mod_ldap | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:10 | mod_lua | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:9 | mod_lua | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:8 | mod_md | 1:2.0.8-8.module_el8.10.0+4295+280de5aa.4 | ALSA-2026:92616 |
| AlmaLinux:10 | mod_proxy_html | 1:2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | mod_proxy_html | 1:2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | mod_proxy_html | 1:2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:10 | mod_session | 2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | mod_session | 2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | mod_session | 2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| AlmaLinux:10 | mod_ssl | 1:2.4.63-13.el10_2.8 | ALSA-2026:89860 |
| AlmaLinux:8 | mod_ssl | 1:2.4.37-65.module_el8.10.0+4332+2bef2e0d.13 | ALSA-2026:92616 |
| AlmaLinux:9 | mod_ssl | 1:2.4.62-13.el9_8.9 | ALSA-2026:88229 |
| Alpine:v3.21 | apache2 | 2.4.69-r0 | ALPINE-CVE-2026-73637 |
| Alpine:v3.22 | apache2 | 2.4.69-r0 | ALPINE-CVE-2026-73637 |
| Alpine:v3.23 | apache2 | 2.4.69-r0 | ALPINE-CVE-2026-73637 |
| Alpine:v3.24 | apache2 | 2.4.69-r0 | ALPINE-CVE-2026-73637 |
| Debian:12 | apache2 | no fix listed | DEBIAN-CVE-2026-73637 |
| Debian:13 | apache2 | 2.4.69-1~deb13u1 | DEBIAN-CVE-2026-73637 |
| Debian:14 | apache2 | 2.4.69-1 | DEBIAN-CVE-2026-73637 |
| Rocky Linux:10 | httpd | 0:2.4.63-13.el10_2.8 | RLSA-2026:89860 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1830+22f0c9e0 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40197+0231e209.8 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1842+4a9649e8.2 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1938+3b7755d4.3 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40206+be2c8a50.8 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40257+286895ef.9 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1984+1bed3124.4 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40312+2c72bb9b.10 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+2061+8d03fdec.5 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40402+af9563a3.13 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40045+6ce8579b.6 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+40053+5a18018e.7 | RLSA-2026:92616 |
| Rocky Linux:8 | httpd | 0:2.4.37-65.module+el8.10.0+1840+b070a976.1 | RLSA-2026:92616 |
| Rocky Linux:9 | httpd | 0:2.4.62-13.el9_8.9 | RLSA-2026:88229 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+40257+286895ef.7 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+40204+716978aa.6 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+40197+0231e209.5 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+2061+8d03fdec.4 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+1938+3b7755d4.3 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+1883+38ed6c58.1 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+1830+22f0c9e0 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_http2 | 0:1.15.7-10.module+el8.10.0+1775+6b057638 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_md | 1:2.0.8-8.module+el8.10.0+40053+5a18018e.2 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_md | 1:2.0.8-8.module+el8.9.0+1370+89cc8ad5 | RLSA-2026:92616 |
| Rocky Linux:8 | mod_md | 1:2.0.8-8.module+el8.10.0+40369+03c444c1.4 | RLSA-2026:92616 |
| Ubuntu:22.04:LTS | apache2 | 2.4.52-1ubuntu4.25 | USN-8931-1 |
| Ubuntu:22.04:LTS | apache2 | 2.4.52-1ubuntu4.25 | UBUNTU-CVE-2026-73637 |
| Ubuntu:24.04:LTS | apache2 | 2.4.58-1ubuntu8.17 | USN-8931-1 |
| Ubuntu:24.04:LTS | apache2 | 2.4.58-1ubuntu8.17 | UBUNTU-CVE-2026-73637 |
| Ubuntu:26.04:LTS | apache2 | 2.4.66-2ubuntu2.6 | UBUNTU-CVE-2026-73637 |
| Ubuntu:26.04:LTS | apache2 | 2.4.66-2ubuntu2.6 | USN-8931-1 |
| Ubuntu:26.10 | apache2 | no fix listed | UBUNTU-CVE-2026-73637 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Apache Software Foundation | Apache HTTP Server | 2.4.0 – through 2.4.68 |
Weakness: CWE-416 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L