CVE-2026-44255 Wazuh: Username Enumeration via Timing Side-Channel
An unauthenticated attacker can enumerate valid usernames by measuring authentication response times, aiding subsequent credential attacks.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-44255?
CVE-2026-44255 is a medium-severity vulnerability in Wazuh Wazuh, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-208
Which versions are affected by CVE-2026-44255?
It affects 1 product.
Products include Wazuh Wazuh.
How do I fix CVE-2026-44255?
No fix has been published for CVE-2026-44255 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-44255 being exploited?
There is no known exploitation of CVE-2026-44255 in the wild and no public exploit code.
Other vulnerabilities in Wazuh Wazuh
- CVE-2025-24016 Wazuh Server Deserialization of Untrusted Data
- CVE-2024-32038 Wazuh Analysis Engine Event Decoder Heap-based Buffer Overflow Remote Code Execution Vulnerability
- CVE-2021-44079 Command injection in n/a
- CVE-2024-1243 Remote code execution and local privilege escalation in Wazuh Windows agent via NetNTLMv2 hash theft
- CVE-2026-61800 Wazuh cluster worker file sync allows arbitrary file write under /var/ossec (incomplete fix for CVE-2026-30893)
Sources
Also known as GHSA-3978-44q9-9px9.