CVE-2026-26204

MEDIUM
Published Apr 29, 2026 Modified Apr 30, 2026 CWE-124 CWE-191

Description

Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 1.0.0 to before version 4.14.4, a heap-based out-of-bounds WRITE occurs in GetAlertData, resulting in writing a NULL byte exactly 1 byte before the start of the buffer allocated by strdup. Due to unsigned integer underflow and pointer arithmetic wrapping, the write lands at offset -1 from the buffer, corrupting heap metadata. A malicious actor can potentially leverage this issue through a compromised agent to cause denial of service or heap corruption by injecting a specially crafted alert into the alerts log file monitored by wazuh-logcollector. This issue has been patched in version 4.14.4.

CVSS v3.1 Score

4.4
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS — Exploit Prediction

0.0002
Probability of exploitation
0.04%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-124 CWE-124
CWE-191 CWE-191

Affected Products

Vendor Product
wazuh wazuh

References

Frequently Asked Questions

What is CVE-2026-26204? +
Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 1.0.0 to before version 4.14.4, a heap-based out-of-bounds WRITE occurs in GetAlertData, resulting in writing a NULL byte exactly 1 byte before the start of the buffer allocated by strdup. Due to unsigned integer underflow and pointer arithmetic wrapping, the write lands at offset -1 from the buffer, corrupting heap metadata. A malicious actor can potentially leverage this issue through a compromised agent to cause denial of service or heap corruption by injecting a specially crafted alert into the alerts log file monitored by wazuh-logcollector. This issue has been patched in version 4.14.4. It has a CVSS v3.1 base score of 4.4 (MEDIUM).
How severe is CVE-2026-26204? +
CVE-2026-26204 has a CVSS v3.1 score of 4.4 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0002, placing it in the 0th percentile for exploitation probability.
What products are affected by CVE-2026-26204? +
CVE-2026-26204 affects products from wazuh, specifically: wazuh. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2026-26204? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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