CVE-2026-42528
Description
A flaw was found in the mod_dav module of the Apache HTTP Server. This vulnerability allows a Denial of Service (DoS) by crashing server child processes. An attacker with permission to create Web Distributed Authoring and Versioning (WebDAV) locks can trigger a memory calculation error during lock operations, terminating active server processes.
Mitigation
If WebDAV functionality is not required, disable the mod_dav module by commenting out the `LoadModule dav_module` line in `/etc/httpd/conf.modules.d/00-dav.conf` or setting `Dav Off` within the relevant configuration contexts.
If WebDAV is required, restrict lock capabilities to authenticated and trusted clients by limiting the LOCK method within the configuration (for example, using `<Limit LOCK>` blocks with strict `Require` directives).
Apply configuration changes by reloading the service:
systemctl reload httpd
Warning: Disabling mod_dav or restricting lock operations will prevent WebDAV clients from acquiring shared or exclusive resource locks. Reloading the httpd service may briefly affect active HTTP connections.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.3 | N/A | 4.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Integrity,Availability,Confidentiality
Technical Impact: DoS: Crash, Exit, or Restart; Execute Unauthorized Code or Commands; Read Memory; Modify Memory
If the incorrect calculation is used in the context of memory allocation, then the software may create a buffer that is smaller or larger than expected. If the allocated buffer is smaller than expected, this could lead to an out-of-bounds read or write (CWE-119), possibly causing a crash, allowing arbitrary code execution, or exposing sensitive data.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
