CVE-2026-71540

Wazuh Manager cluster header parsing allows pre-authentication memory exhaustion

HIGH
7.5
CVSS Score
Published: September 24, 2026 at 05:49 PM UTC
Updated: September 30, 2026 at 07:38 PM UTC
1 product affected across 1 vendorWazuh

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
PoC

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 4.14.7
Affected range stops below 4.14.7, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

7.5HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusAWAITING ANALYSIS
CWE
CWE-770

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