CVE-2025-55753
Apache HTTP Server: mod_md (ACME), unintended retry intervals
- State
- Published
- Severity
- 7.5 High
- Published
- Dec 5, 2025
- Updated
- Dec 5, 2025
- Reserved
- Aug 15, 2025
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N | CISA-ADP |
Weaknesses
- CWE-190 Integer Overflow or Wraparound
Affected Products
| Product | Versions |
|---|---|
Apache HTTP ServerApache Software Foundation |
|
References
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