CVE-2025-55753

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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
UNKNOWN
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apacheCNA
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Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Debian logo
Debian Releases
Debian Product
Codename
apache2
bullseye
vulnerable
bullseye (security)
vulnerable
bookworm
vulnerable
bookworm (security)
vulnerable
trixie
vulnerable
forky
vulnerable
sid
vulnerable
Common Weakness Enumeration
References
https://httpd.apache.org/security/vulnerabilities_24.html
http://www.openwall.com/lists/oss-security/2025/12/04/4