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

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.

Published: 2025-12-05 Last update: 2025-12-10 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2025-55753 is rated Low Risk (35.1/100): CVSS High severity, with low exploitation likelihood (EPSS 0.05%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2025-55753

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-05-02 0.08% 0.05% -0.04%
2 2025-12-11 0.01% 0.08% +0.07%
3 2025-12-05 — 0.01% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2025-55753

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 3.6 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2025-55753

OS Trackers for CVE-2025-55753

vendor priority summary link
alpine — CVE-2025-55753: 1 source package rows (apache2); 5 state rows across 5 repos (3.20-main, 3.21-main, 3.22-main, 3.23-main, edge-main); fixed 5, open 0. https://security.alpinelinux.org/vuln/CVE-2025-55753
debian not yet assigned CVE-2025-55753 not yet assigned priority: Debian including 1 source packages (apache2), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2025-55753
redhat high — https://access.redhat.com/security/cve/CVE-2025-55753
suse medium CVE-2025-55753 severity moderate: SUSE including 313 source package names (2.1.3-4.26:wpa_supplicant-2.10-5.1, 2.1.3-4.27:wpa_supplicant-2.10-5.1, …), 536 product×package rows across 97 product lines (Container suse/manager/4.3/proxy-httpd, Container suse/manager/5.0/x86_64/proxy-httpd, … (97 product lines)): Fixed 285, Known Affected 231, Known Not Affected 13, First Fixed 7. https://www.suse.com/security/cve/CVE-2025-55753/
ubuntu low CVE-2025-55753 low priority: Ubuntu including 1 source packages (apache2), 9 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): needs-triage 4, released 4, ignored 1. https://ubuntu.com/security/CVE-2025-55753

Affected software / configurations for CVE-2025-55753

Vendor Product Version Raw CPE
apache http_server >= 2.4.30, < 2.4.66 cpe:2.3:a:apache:http_server:*:*:*:*:*:*:*:*

References for CVE-2025-55753

cvelogic Threat Intelligence