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 mod_proxy_htmlUpgrade httpd-manualUpgrade httpd-develUpgrade httpdUpgrade mod_mdUpgrade mod_sslUpgrade mod_http2Upgrade httpd-toolsUpgrade httpd-filesystemUpgrade mod_sessionUpgrade mod_ldap | Dec 23, 2025 | Dec 22, 2025 |
| Alpine Linux | — | Upgrade apache2 | Dec 8, 2025 | Dec 5, 2025 |
| Amazon Linux Ami 2 | — | Upgrade mod_mdUpgrade httpd-manualUpgrade mod_sessionUpgrade mod_proxy_htmlUpgrade httpd-toolsUpgrade httpd-develUpgrade mod_sslUpgrade httpd-debuginfoUpgrade httpdUpgrade httpd-filesystemUpgrade 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_proxy_htmlUpgrade mod_sslUpgrade httpd-filesystemUpgrade httpd-manualUpgrade mod_mdUpgrade httpdUpgrade mod_sessionUpgrade httpd-develUpgrade httpd-toolsUpgrade mod_ldapUpgrade mod_http2 | Dec 24, 2025 | Dec 5, 2025 |
| Redhat_linux | — | Upgrade mod_ssl-debuginfoUpgrade mod_http2Upgrade mod_http2-debugsourceUpgrade httpd-toolsUpgrade mod_proxy_html-debuginfoUpgrade httpd-manualUpgrade mod_md-debugsourceUpgrade mod_proxy_htmlUpgrade mod_ldapUpgrade mod_ldap-debuginfoUpgrade httpd-filesystemUpgrade mod_mdUpgrade mod_sslUpgrade mod_session-debuginfoUpgrade mod_http2-debuginfoUpgrade httpd-debuginfoUpgrade httpdUpgrade httpd-tools-debuginfoUpgrade httpd-debugsourceUpgrade mod_md-debuginfoUpgrade httpd-develUpgrade mod_session | Dec 23, 2025 | Dec 5, 2025 |
| Rocky_linux | — | Upgrade httpd-tools-debuginfoUpgrade httpd-develUpgrade mod_md-debugsourceUpgrade httpd-toolsUpgrade httpdUpgrade mod_http2-debugsourceUpgrade mod_ssl-debuginfoUpgrade mod_mdUpgrade mod_http2-debuginfoUpgrade mod_ldapUpgrade mod_ldap-debuginfoUpgrade mod_sslUpgrade mod_proxy_htmlUpgrade httpd-debugsourceUpgrade mod_sessionUpgrade mod_proxy_html-debuginfoUpgrade mod_session-debuginfoUpgrade mod_http2Upgrade mod_md-debuginfoUpgrade httpd-debuginfo | Feb 5, 2026 | Dec 23, 2025 |
| Suse | — | Upgrade apache2-develUpgrade apache2-tls13-utilsUpgrade apache2-tls13-workerUpgrade apache2-workerUpgrade apache2-example-pagesUpgrade apache2-tls13-develUpgrade apache2-manualUpgrade apache2-tls13-preforkUpgrade apache2-tls13Upgrade apache2Upgrade apache2-utilsUpgrade apache2-preforkUpgrade apache2-docUpgrade apache2-tls13-example-pagesUpgrade apache2-tls13-docUpgrade apache2-event | Apr 15, 2026 | Dec 23, 2025 |
| Ubuntu | — | Upgrade apache2 (Ubuntu Pro)Upgrade apache2 | 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