Wazuh Manager cluster header parsing allows pre-authentication memory exhaustion (CVE-2026-71540) | HOL Guard CVE

High · CVSS 7.5CVE-2026-71540

Wazuh Manager cluster header parsing allows pre-authentication memory exhaustion

Answer in brief

CVE-2026-71540 records a High severity (CVSS 7.5) vulnerability in Wazuh Manager cluster header parsing allows pre-authentication memory exhaustion. The current sources do not mark it as known exploited. The current feed maps wazuh/wazuh (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 24, 2026Updated Sep 24, 2026Source checked Sep 25, 2026First seen by HOL Sep 25, 2026Material review Sep 24, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps wazuh/wazuh (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
wazuh/wazuhgeneric	>=3.9.0 <4.14.7	4.14.7

Recommended response

Check inventory. Check lockfiles and deployed manifests for wazuh/wazuh.
Review the reported fix. Update wazuh/wazuh to 4.14.7 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 24, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 25, 2026

Sources and claim methodology

Upstream source description

Wazuh is an open-source security platform providing unified XDR and SIEM protection for endpoints and cloud workloads. From 3.9.0 until 4.14.7, wazuh-clusterd in framework/wazuh/core/cluster/common.py allocates a payload buffer using the size declared in a 20-byte cluster protocol header before Fernet decryption validates the peer. An unauthenticated network peer can declare a payload of up to 256 MiB, stop sending after the header, and retain that allocation until the TCP connection closes. The cluster listener has no application-level per-source connection budget in affected versions, allowing concurrent sockets to multiply memory consumption and potentially terminate the cluster process, disrupt synchronization, and interrupt distributed API forwarding. This issue is fixed in version 4.14.7.

Quoted source text, attributed separately from HOL analysis.