# CVE-2026-44255: Wazuh username enumeration via authentication timing attack

Source: https://junglewise.ai/threats/cve-2026-44255-wazuh-username-enumeration-via-authentication-timing-attack  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-19. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-44255 · Severity: medium · CVSS 5.3 · Published 2026-08-19

Wazuh is a security platform used for threat detection and response across corporate networks. The authentication system has a timing vulnerability that allows unauthenticated attackers to determine valid usernames by measuring authentication response times. Attackers can exploit this information to refine credential-guessing attacks and gain unauthorized access to the platform.

Technologies: [Wazuh](https://junglewise.ai/threats/technologies/wazuh). Vendors: [Wazuh](https://junglewise.ai/threats/vendors/wazuh).

## Quick answers

**Is CVE-2026-44255 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-44255 being exploited in the wild.

**How severe is CVE-2026-44255?** Medium severity, with a CVSS score of 5.3, published 19 August 2026.

**Which products and versions are affected?** Wazuh 4.0.0 to 4.14.5, 5.0.0-beta1.

**Is there a fix for CVE-2026-44255?** A patch was published on 2026-04-28: Fix merged in versions 4.14.6 and 5.0.0-beta2 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-44255 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-44255?** Check whether you run Wazuh at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The vulnerability is a timing-based information disclosure flaw in AuthenticationManager.check_user() within framework/wazuh/rbac/orm.py. When an invalid username is supplied, the function returns immediately without performing password validation. When a valid username is supplied, an expensive bcrypt hash calculation is performed, causing a measurable delay. An unauthenticated remote attacker can compare authentication response times to infer whether a username exists in the system. This enables username enumeration attacks that can be chained with credential-guessing techniques. The fix involves performing a dummy bcrypt calculation on all authentication attempts to ensure constant-time operation, regardless of username validity.

## Affected products

- Wazuh Wazuh 4.0.0 to 4.14.5, 5.0.0-beta1

## Timeline

- 2026-08-19: disclosed
- 2026-04-28: patched: Fix merged in versions 4.14.6 and 5.0.0-beta2

## References

- [https://github.com/wazuh/wazuh/commit/5ecea7b38b998407cb0d205467dd247140a0f981](https://github.com/wazuh/wazuh/commit/5ecea7b38b998407cb0d205467dd247140a0f981)
- [https://github.com/wazuh/wazuh/pull/35757](https://github.com/wazuh/wazuh/pull/35757)

## Related threats

- [Wazuh heap buffer overflow in Windows EventChannel decoder](https://junglewise.ai/threats/cve-2026-62365-wazuh-is-an-open-source-security-platform-providing-unified-xdr)
- [Wazuh unauthenticated memory exhaustion in cluster listener](https://junglewise.ai/threats/cve-2026-71540-wazuh-is-an-open-source-security-platform-providing-unified-xdr)
- [Wazuh stack exhaustion in XML parser via element attributes](https://junglewise.ai/threats/cve-2026-61811-wazuh-is-an-open-source-security-platform-providing-unified-xdr)
- [Wazuh cluster key disclosure in GET /cluster/local/config](https://junglewise.ai/threats/cve-2026-61802-wazuh-cluster-key-disclosure-in-get-cluster-local-config)
- [Wazuh arbitrary file write in cluster worker file sync](https://junglewise.ai/threats/cve-2026-61800-wazuh-arbitrary-file-write-in-cluster-worker-file-sync)