What is CVE-2025-55753?

CVE-2025-55753 is a high-severity vulnerability in Apache Http Server, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2025-12-05.

How severe is CVE-2025-55753?

High severity. CVSS v3 base score is 7.5 out of 10.

Integer overflow in Apache Http Server

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.

Vulnerability class: Integer Overflow

EPSS: 0.004 (34.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

Affected products

Apache Http_server
Apache Software Foundation Http Server — versions 2.4.30

Weakness classification (CWE)

CWE-190 — Integer Overflow or Wraparound

References

security@apache.org (vendor-advisory, Vendor Advisory)
af854a3a-2127-422b-91ae-364da2661108 (Issue Tracking, Third Party Advisory)

Frequently asked questions

What is CVE-2025-55753?: CVE-2025-55753 is a high-severity vulnerability in Apache Http Server, classified under Integer Overflow or Wraparound. CVSS score: 7.5/10. Published 2025-12-05.
How severe is CVE-2025-55753?: High severity. CVSS v3 base score is 7.5 out of 10.