vulnerability
Red Hat: CVE-2025-55753: mod_md: Apache HTTP Server: mod_md (ACME), unintended retry intervals (Multiple Advisories)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 8 | (AV:N/AC:L/Au:N/C:C/I:N/A:N) | Dec 5, 2025 | Dec 23, 2025 | Jan 7, 2026 |
Severity
8
CVSS
(AV:N/AC:L/Au:N/C:C/I:N/A:N)
Published
Dec 5, 2025
Added
Dec 23, 2025
Modified
Jan 7, 2026
Description
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.
Solutions
redhat-upgrade-httpdredhat-upgrade-httpd-debuginforedhat-upgrade-httpd-debugsourceredhat-upgrade-httpd-develredhat-upgrade-httpd-filesystemredhat-upgrade-httpd-manualredhat-upgrade-httpd-toolsredhat-upgrade-httpd-tools-debuginforedhat-upgrade-mod_http2redhat-upgrade-mod_http2-debuginforedhat-upgrade-mod_http2-debugsourceredhat-upgrade-mod_ldapredhat-upgrade-mod_ldap-debuginforedhat-upgrade-mod_mdredhat-upgrade-mod_md-debuginforedhat-upgrade-mod_md-debugsourceredhat-upgrade-mod_proxy_htmlredhat-upgrade-mod_proxy_html-debuginforedhat-upgrade-mod_sessionredhat-upgrade-mod_session-debuginforedhat-upgrade-mod_sslredhat-upgrade-mod_ssl-debuginfo
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