VulnerabilityPublished 10 Jul 2025Updated 4 Nov 2025

CVE-2025-53020: Apache HTTP Server · Memory Leak

Affects Apache HTTP ServerSource CVE Database V5

Not known to be exploited · CVSS 7.5 High : upgrade to 2.4.64 soon.

Data as of 26 Oct 2026, 10:12 UTC

CVSS 3.1 base score

7.5High

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 4.9% chance of exploitation in 30 days – higher than 92% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 2.4.64

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: High: There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 10 Jul 2025
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade apache/httpd to 2.4.64.

Affected software

Product	Affected	Fixed in
Apacheapache/httpd`pkg:rpm/apache/httpd`Other threats	Affected <2.4.64	Fixed in 2.4.64

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

The most effective mitigation is to upgrade all affected Apache HTTP Server instances to version 2.4.64 or later, which contains the fix for this memory leak vulnerability. Organizations should implement a robust patch management process to ensure timely deployment of security updates. In environments where immediate patching is not feasible, administrators should monitor server memory usage closely and consider implementing resource limits or automated restarts to mitigate potential DoS conditions. Network-level protections such as rate limiting, web application firewalls (WAFs), and intrusion detection systems (IDS) can help detect and block abnormal traffic patterns that might trigger the vulnerability. Additionally, conducting regular security audits and vulnerability scans can help identify outdated Apache versions. For critical infrastructure, deploying redundant servers and load balancers can reduce the impact of any single server failure. Finally, maintaining comprehensive logging and alerting on server performance metrics will enable rapid detection and response to exploitation attempts.

Description

Late Release of Memory after Effective Lifetime vulnerability in Apache HTTP Server. This issue affects Apache HTTP Server: from 2.4.17 up to 2.4.63. Users are recommended to upgrade to version 2.4.64, which fixes the issue.

Impact

For European organizations, the primary impact of CVE-2025-53020 is the potential for denial of service caused by memory exhaustion on Apache HTTP Servers. This can lead to downtime of critical web services, affecting business operations, customer access, and internal communications. Sectors such as finance, government, healthcare, and e-commerce, which heavily depend on reliable web infrastructure, could face operational disruptions and reputational damage. The vulnerability’s remote exploitability without authentication increases the risk of automated attacks or scanning by threat actors. Additionally, prolonged service outages could have regulatory implications under EU laws like GDPR if services handling personal data become unavailable or unstable. While no data breach risk is directly associated, the availability impact alone can have cascading effects on business continuity and incident response resources. Organizations with large-scale deployments of Apache HTTP Server or those hosting critical public services are particularly vulnerable to targeted or opportunistic exploitation attempts.

CWE-401Missing Release of Memory after Effective Lifetime (opens in a new tab)
Variant weaknessLikelihood of exploit: Medium
The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.
Implementation · Libraries or Frameworks
Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone.
Architecture and Design
Use an abstraction library to abstract away risky APIs. Not a complete solution.
Architecture and Design · Build and Compilation
Consider using the Boehm-Demers-Weiser garbage collector (bdwgc), which can help avoid leaks.
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Nov 2025, 06:29 UTC

WeaknessesCWE-401

Technical details

References

Community reviews

Related threats