Integer Overflow Vulnerability in Apache HTTP Server
CVE-2025-55753

7.5HIGH

Key Information:

Vendor

Apache
Status
Apache Http Server
Vendor
CVE Published:
5 December 2025

What is CVE-2025-55753?

An integer overflow vulnerability exists in Apache HTTP Server that occurs during ACME certificate renewal processes. If renewal attempts fail several times, the backoff timer can reset to zero after approximately 30 days in default configurations. This results in repeated attempts to renew the certificate without any delay, potentially leading to excessive requests and service disruptions. To mitigate this risk, users are advised to update to Apache HTTP Server version 2.4.66 or later, which addresses this issue.

Affected Version(s)

Apache HTTP Server 2.4.30 < 2.4.66

References

https://httpd.apache.org/security/vulnerabilities_24.html
vendor-advisory

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
High
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Aisle Research
JSON
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CVE-2025-55753 : Integer Overflow Vulnerability in Apache HTTP Server