CVE-2025-55753

Name	CVE-2025-55753
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
Debian Bugs	1121926

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
apache2 (PTS)	bullseye	2.4.62-1~deb11u1	vulnerable
	bullseye (security)	2.4.65-1~deb11u1	vulnerable
	bookworm	2.4.65-1~deb12u1	vulnerable
	bookworm (security)	2.4.62-1~deb12u2	vulnerable
	trixie	2.4.65-2	vulnerable
	forky	2.4.65-3	vulnerable
	sid	2.4.66-2	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
apache2	source	(unstable)	2.4.66-1			1121926

Notes

[trixie] - apache2 <no-dsa> (Minor issue)
[bookworm] - apache2 <no-dsa> (Minor issue)
[bullseye] - apache2 <postponed> (Minor issue)
https://httpd.apache.org/security/vulnerabilities_24.html#CVE-2025-55753
https://github.com/apache/httpd/commit/ab9dd8e2cfe7d62efe5ff8925fbef1de756a2fc2