An integer overflow in the case of failed ACME certificate renewal leads, after a number of failures (~30 days in default configurations), to the backoff timer becoming 0. Attempts to renew the certificate then are repeated without delays until it succeeds.
This issue affects Apache HTTP Server: from 2.4.30 before 2.4.66.
Users are recommended to upgrade to version 2.4.66, which fixes the issue.
CVSS Details
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alma_linux | — | Upgrade httpd-develUpgrade httpd-manualUpgrade mod_sslUpgrade mod_proxy_htmlUpgrade httpdUpgrade mod_mdUpgrade mod_ldapUpgrade httpd-toolsUpgrade mod_http2Upgrade httpd-filesystemUpgrade mod_session | Dec 23, 2025 | Dec 22, 2025 |
| Alpine Linux | — | Upgrade apache2 | Dec 8, 2025 | Dec 5, 2025 |
| Amazon Linux Ami 2 | — | Upgrade httpd-develUpgrade httpd-manualUpgrade mod_sslUpgrade mod_sessionUpgrade mod_proxy_htmlUpgrade mod_mdUpgrade httpd-toolsUpgrade httpdUpgrade httpd-filesystemUpgrade httpd-debuginfoUpgrade mod_ldap | May 20, 2026 | May 20, 2026 |
| Apache Httpd | — | Upgrade to the latest version of Apache HTTPD | Dec 8, 2025 | Dec 5, 2025 |
| Apple Osx Apache | — | Upgrade macOS to the latest version | Mar 27, 2026 | Mar 24, 2026 |
| Debian | — | Upgrade apache2 | Jan 12, 2026 | Jan 12, 2026 |
| Freebsd | — | Upgrade apache24 | Dec 10, 2025 | Dec 4, 2025 |
| Gentoo Linux | — | Upgrade www-servers/apache. | Aug 16, 2026 | Aug 13, 2026 |
| Oracle_linux | — | Upgrade mod_http2Upgrade mod_ldapUpgrade httpd-toolsUpgrade httpdUpgrade mod_sessionUpgrade httpd-develUpgrade httpd-filesystemUpgrade mod_mdUpgrade httpd-manualUpgrade mod_sslUpgrade mod_proxy_html | Dec 24, 2025 | Dec 5, 2025 |
| Redhat_linux | — | Upgrade mod_sessionUpgrade mod_mdUpgrade mod_md-debuginfoUpgrade httpd-filesystemUpgrade httpd-tools-debuginfoUpgrade httpd-debugsourceUpgrade mod_sslUpgrade mod_http2-debuginfoUpgrade mod_session-debuginfoUpgrade httpdUpgrade httpd-debuginfoUpgrade httpd-develUpgrade mod_md-debugsourceUpgrade mod_proxy_htmlUpgrade mod_http2-debugsourceUpgrade mod_proxy_html-debuginfoUpgrade mod_ldap-debuginfoUpgrade mod_ssl-debuginfoUpgrade mod_http2Upgrade httpd-manualUpgrade mod_ldapUpgrade httpd-tools | Dec 23, 2025 | Dec 5, 2025 |
| Rocky_linux | — | Upgrade httpd-tools-debuginfoUpgrade mod_mdUpgrade mod_md-debugsourceUpgrade httpdUpgrade mod_http2-debuginfoUpgrade httpd-develUpgrade httpd-toolsUpgrade mod_http2-debugsourceUpgrade mod_ssl-debuginfoUpgrade httpd-debuginfoUpgrade mod_session-debuginfoUpgrade mod_http2Upgrade mod_sessionUpgrade mod_md-debuginfoUpgrade mod_ldap-debuginfoUpgrade mod_sslUpgrade mod_ldapUpgrade mod_proxy_htmlUpgrade mod_proxy_html-debuginfoUpgrade httpd-debugsource | Feb 5, 2026 | Dec 23, 2025 |
| Suse | — | Upgrade apache2-tls13-preforkUpgrade apache2-tls13-docUpgrade apache2Upgrade apache2-eventUpgrade apache2-manualUpgrade apache2-docUpgrade apache2-preforkUpgrade apache2-tls13-example-pagesUpgrade apache2-utilsUpgrade apache2-tls13Upgrade apache2-tls13-develUpgrade apache2-tls13-utilsUpgrade apache2-develUpgrade apache2-example-pagesUpgrade apache2-tls13-workerUpgrade apache2-worker | Apr 15, 2026 | Dec 23, 2025 |
| Ubuntu | — | Upgrade apache2Upgrade apache2 (Ubuntu Pro) | Jan 20, 2026 | Dec 5, 2025 |
| Vmware Photon_os | — | Use 'tdnf update' to upgrade all packages to the latest version. | Feb 9, 2026 | Dec 5, 2025 |
Prioritise with Active Threat Intelligence
With curated Threat Intelligence, you can see which vulnerabilities truly put you at risk, prioritize what matters most, and act before attackers do.
Explore Intelligence Hub