CVE-2026-71540

HIGHPre-NVD 7.57.5
EchelonGraph scoreLOW confidence

This high-severity CVE scores 7.5 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: secondary
7.5EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: —CVSS: 7.5Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

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.

CVSS v3
7.5
EG Score
7.5(low)
EG Risk
38(Track)
EG Risk 38/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity75% × 45%
Exploitation0% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
—
EPSS %ILE
—
KEV
Not listed

Published

September 24, 2026

Last Modified

September 24, 2026

Advisory Details (4)

Auto-updated Sep 24, 2026
🔬 Proof of concept available. Patch available. Sources: github_commit, github_release, github, github_pr.
github_release Patch Available

Wazuh v4.14.7

Patch available: wazuh/wazuh v4.14.7

https://github.com/wazuh/wazuh/releases/tag/v4.14.7
github_commit Patch Available

commit 9a996bc23d28 (wazuh/wazuh)

Patch available: wazuh/wazuh v5.0.0-beta3 (contains commit 9a996bc23d28)

https://github.com/wazuh/wazuh/commit/9a996bc23d28725f6c1f8f7808355d90e20d3382
github_pr Patch Available

Defer cluster payload buffer allocation until data is received

Patch available: wazuh/wazuh v5.0.0-beta3 (PR #37280 merged 2026-06-30)

https://github.com/wazuh/wazuh/pull/37280
github Patch Available🟡 PoC Available

pre-authentication memory amplification in cluster header parsing lets one source IP allocate 256 MiB of master memory per TCP connection on Wazuh manager · Advisory · wazuh/wazuh · GitHub

https://github.com/wazuh/wazuh/security/advisories/GHSA-78wx-4r6w-w73f

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 3× in last 7d / 3× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-24 18:35 UTCEG score recompute
  2. 2026-09-24 17:57 UTCEG score recompute
  3. 2026-09-24 17:56 UTCMITRE cvelistV5first tracked

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Frequently asked(4)

What is CVE-2026-71540?
CVE-2026-71540 is a high vulnerability published on September 24, 2026. 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…
When was CVE-2026-71540 disclosed?
CVE-2026-71540 was first published in the National Vulnerability Database on September 24, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-71540?
CVE-2026-71540 has a CVSS v3 base score of 7.5 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
How do I remediate CVE-2026-71540?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-71540, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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