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

Published Dec 4, 2025
·
Updated

802.1X. An authentication issue was addressed with improved state management.

Other sources

Accounts. An authorization issue was addressed with improved state management.

— Apple

Admin Framework. A path handling issue was addressed with improved validation.

— Apple

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.

— Launchpad

Apache HTTP Server: modmd (ACME), unintended retry intervals

— Microsoft

apache. This is a vulnerability in open source code and Apple Software is among the affected projects. The CVE-ID was assigned by a third party. Learn more about the issue and CVE-ID at cve.org.

— Apple

Credit

Rosyna Keller(Totally Not Malicious Software), Ryan Dowd@@_rdowd, CVE-2025-55753, CVE-2025-58098, CVE-2025-59775, CVE-2025-65082, CVE-2025-66200, Mickey Jin@@patch1t, an anonymous researcher, Koh M. Nakagawa@@tsunek0h(FFRI Security Inc), Talal Haj Bakry(Mysk Inc), Tommy Mysk@@mysk_co(Mysk Inc), Zhongquan Li@@Guluisacat, Justin Cohen(Google), Jex Amro, Cristian Dinca (icmd.tech), Hossein Lotfi@@hosselot(TrendAI Zero Day Initiative), YingQi Shi@@Mas0nShi(DBAppSecurity's WeBin lab), Mustafa Calap@@ordinal0, dbg.re), Etienne Charron (Renault), Victoria Martini (Renault), Zhongcheng Li(IES Red Team), Andreas Jaegersberger & Ro Achterberg(Nosebeard Labs), Asaf Cohen, CVE-2025-14524, 风沐云烟@@binary_fmyy, Minghao Lin@@Y1nKoc, Jonathan Bar Or@@yo_yo_yo_jbo, DARKNAVY@@DarkNavyOrg, XiguaSec, Ye Zhang(Baidu Security), Ryan Dowd@@_rdowd(Iru), Csaba Fitzl@@theevilbit(Iru), CVE-2025-64505, Joseph Ravichandran@@0xjprx(MIT CSAIL), Gor Aleksanyan(BoB 0xB6), Dhiyanesh Selvaraj@@redroot97(BoB 0xB6), 이동하 (Lee Dong Ha(BoB 0xB6), Jian Lee@@speedyfriend433, hari shanmugam, Johnny Franks@@0xjohnny, Yuebin Sun@@yuebinsun2020(SecuRing), an anonymous researcher(SecuRing), Nathaniel Oh@@calysteon(SecuRing), Kirin@@Pwnrin(SecuRing), Wojciech Regula(SecuRing), Joshua Jewett@@JoshJewett33, Ilya Andr (andrd3v)(RTU MIREA), Ilias Morad (A2nkF)(Voynich Group), Duy Trần@@khanhduytran0, @@hugeBlack, Himanshu Bharti@@Xpl0itme(Khatima), Rodolphe Brunetti@@eisw0lf(Lupus Nova), Matej Moravec@@MacejkoMoravec, Dawuge(Shuffle Team), Hunan University, Gergely Kalman@@gergely_kalman, Andrei Dodu, Morris Richman@@morrisinlife, Kun Peeks@@SwayZGl1tZyyy, Dave G., Gyujeong Jin at Team.0xb6@@G1uN4sh, wdszzml, Atuin Automated Vulnerability Discovery Engine, Alex Radocea, Christian Kohlschütter, Sreejith Krishnan R, @@pixiepointsec, Luke Roberts@@rookuu, Pedro Tôrres@@t0rr3sp3dr0, Caspian Tarafdar, Andrew Becker, webb, Thomas Espach, @@hamayanhamayan, Yeonghyeon Choi, Daniel Rhea, Söhnke Benedikt Fischedick (Tripton), Emrovsky & Switch3301, Yevhen Pervushyn, Minse Kim, Narcis Oliveras Fontàs, Nathaniel Oh@@calysteon, Hongze Wu(Ant Group Infrastructure Security Team), Shuaike Dong(Ant Group Infrastructure Security Team), greenbynox, Arni Hardarson, Gongyu Ma@@Mezone0, Héloïse Gollier, Mathy Vanhoef (KU Leuven), Johnny Franks (zeroxjf), Amy (amys.website), @@cloudlldb, Kirin@@Pwnrin, Chunyu Song(NorthSea)

Affected Software

10 affected componentsFixes available
Apache HTTP Server>2.4.30<=2.4.66
Apache HTTP Server>=2.4.30<2.4.66
Microsoft cbl2 httpd 2.4.65-1
Patch available
Microsoft azl3 httpd 2.4.65-1
Patch available
Apple macOS Sequoia<15.7.5
15.7.5
Apple macOS Sonoma<14.8.5
14.8.5
Apple macOS Tahoe<26.4
26.4
debian/apache2<=2.4.62-1~deb11u1
2.4.67-1~deb11u12.4.67-1~deb12u22.4.67-1~deb13u22.4.67-1
IBM DS8A00( R10.0 - R10.1 )<=10.1.3.0 - 10.11.35.0
IBM DS8900F ( R9.4)<=89.40.83.0-89.44.25.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 15.7.5
  2. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 14.8.5
  3. Upgrade

    Upgrade to a fixed release to a version that resolves this vulnerability.

    Fixed in 26.4
  4. Upgrade

    Upgrade debian/apache2 to a version that resolves this vulnerability.

    Fixed in 2.4.67-1~deb11u1Fixed in 2.4.67-1~deb12u2Fixed in 2.4.67-1~deb13u2Fixed in 2.4.67-1
  5. Upgrade

    Upgrade Apache HTTP Server to a version that resolves this vulnerability.

    Fixed in 2.4.66Patch CVE-2025-55753

Event History

Dec 5, 2025
CVE Published
via MITRE·10:12 AM
Data Sourced
via MITRE·10:12 AM
DescriptionWeakness
Data Sourced
via Red Hat·11:01 AM
DescriptionSeverityAffected Software
Data Sourced
via NVD·11:15 AM
DescriptionSeverityWeaknessAffected Software
Dec 11, 2025
Data Sourced
via Microsoft·01:02 AM
DescriptionSeverityWeaknessAffected Software
Updated
via Microsoft·01:02 AM
Affected Software
Updated
via Microsoft·01:02 AM
DescriptionSeverity
Mar 24, 2026
Data Sourced
via Apple·12:00 AM
DescriptionWeaknessAffected Software
Updated
via Apple·12:00 AM
DescriptionWeakness
Updated
via Apple·12:00 AM
DescriptionWeaknessAffected Software
Updated
via Apple·12:00 AM
Affected Software
May 28, 2026
Data Sourced
via Ubuntu·06:16 PM
RemedyDescriptionSeverityAffected Software
Data Sourced
via Debian·06:17 PM
DescriptionAffected Software
Data Sourced
via Launchpad·06:17 PM
Description
Aug 19, 2026
Data Sourced
via IBM·12:00 AM
DescriptionAffected Software

Parent advisories

This vulnerability appears in the following advisories.

Peer vulnerabilities

Found alongside the following vulnerabilities.

Frequently Asked Questions

1

What is the severity of CVE-2025-55753?

CVE-2025-55753 is classified as a moderate severity vulnerability due to the potential for repeated certificate renewal attempts without delays.

2

How do I fix CVE-2025-55753?

To fix CVE-2025-55753, you should upgrade your Apache HTTP Server to a version higher than 2.4.66.

3

What products are affected by CVE-2025-55753?

CVE-2025-55753 affects Apache HTTP Server versions between 2.4.30 and 2.4.66.

4

What is the impact of CVE-2025-55753 on my server?

The impact of CVE-2025-55753 can lead to excessive load and potential downtime due to unregulated certificate renewal attempts.

5

How can I determine if I am vulnerable to CVE-2025-55753?

You can determine vulnerability to CVE-2025-55753 by checking your Apache HTTP Server version and ensuring it is above 2.4.66.

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