High 7.5Published Dec 5, 2025

CVE-2025-55753Apache HTTP Server: mod_md (ACME), unintended retry intervals

Updated under an hour ago (Oct 27, 2026, 5:40 PM ET)

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It affects Apache Software Foundation Apache HTTP Server and 1 other product. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Apache Software Foundation Apache HTTP Server

Exploited in the last 30 days

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: 7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
Weakness (CWE): CWE-190
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: apache
NVD analysis: Analyzed
Record last updated: Dec 5, 2025
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Apache Software Foundation Apache HTTP Server apache_software_foundation:apache_http_server (from the name)	from 2.4.30 before 2.4.66	CNA record
apache http_server apache:http_server	from 2.4.30 before 2.4.66	NVD

References

References

https://httpd.apache.org/security/vulnerabilities_24.html	vendor-advisory
http://www.openwall.com/lists/oss-security/2025/12/04/4	issue-tracking, third-party-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.