# CVE-2026-62365: Wazuh: Heap Buffer Overflow in DecodeWinevt() join_data Accumulation via Crafted EventChannel XML

Status: published. Published: 2026-11-04. Updated: 2026-11-04.

Wazuh is an open-source security platform providing unified XDR and SIEM protection for endpoints and cloud workloads. DecodeWinevt in src/analysisd/decoders/winevtchannel.c accumulates unnamed Windows EventChannel Data element contents into the fixed 65,535-byte join_data heap buffer but passes the growing content length, rather than the OS_MAXSTR buffer capacity, as the snprintf size. An enrolled agent can submit an EventChannel message containing four maximum-sized unnamed Data elements, causing the fourth accumulation to write beyond join_data and corrupt adjacent heap metadata. The subsequent free of join_data2 causes the wazuh-analysisd process to terminate, stopping log ingestion for all agents handled by that manager. This vulnerability is fixed in 4.14.7.

## Remediation

No remediation reported in collected sources

## Affected products and versions

- wazuh / wazuh: >= 3.9.0, < 4.14.7 (affected). Source: CNA: GitHub_M

## Severity and prioritization

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H; source: CNA: GitHub_M

- CVSS 3.1: 5.3 (medium); CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: Not available

- SSVC: Not available

- Weaknesses: CWE-122

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/wazuh/wazuh/security/advisories/GHSA-whhr-gxxr-f6pm (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/wazuh/wazuh/pull/37198 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/wazuh/wazuh/commit/07c5b2829f671eac0436412701a346a26555fdc7 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/wazuh/wazuh/releases/tag/v4.14.7 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/wazuh/wazuh/commit/07c5b2829f671eac0436412701a346a26555fdc7 (security-advisories@github.com)

- https://github.com/wazuh/wazuh/pull/37198 (security-advisories@github.com)

- https://github.com/wazuh/wazuh/releases/tag/v4.14.7 (security-advisories@github.com)

- https://github.com/wazuh/wazuh/security/advisories/GHSA-whhr-gxxr-f6pm (security-advisories@github.com)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-62365; retrieved 2026-11-04; source updated 2026-11-04

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-62365; retrieved 2026-11-05; source updated 2026-11-04

Revision: 2cd959a28bdb235cd8a6d4eee871f3ebcef4a2938bfe5f129b13376fdf384f39

Canonical: https://y2.dev/cve/CVE-2026-62365

## Agent and API access

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- WebMCP: search_cve_disclosures, get_cve_disclosure, get_cve_page_markdown, get_y2_cve_access. Available in compatible browsers.

- Cyber API: https://api.y2.dev/api/v2/cyber/cves and https://api.y2.dev/api/v2/cyber/cves/{cveId}.

- Y2 Pro or Elite: create a workspace API key with the intel:cyber scope and send Authorization: Bearer <Y2_API_KEY>. Setup: https://y2.dev/docs/api/create-key.

- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

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