CVE-2026-41499: wazuh Integer Underflow — Fix

Description

Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 4.0.0 to before version 4.14.4, multiple heap-based out-of-bounds WRITE vulnerabilities exist in parse_uname_string() (remoted_op.c). This function processes OS identification data from agents and contains a dangerous code pattern that appears in 4 locations within the same function: writing to strlen(ptr) - 1 without checking for empty strings. When the string is empty, strlen() returns 0, and 0 - 1 wraps to SIZE_MAX due to unsigned integer underflow. Due to pointer arithmetic wrapping, SIZE_MAX effectively becomes -1, causing a write exactly 1 byte before the allocated buffer. This corrupts heap metadata (e.g., the chunk size field in glibc malloc), leading to heap corruption. This issue has been patched in version 4.14.4.

Is your site exposed to CVE-2026-41499?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

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

EPSS — Exploit Prediction

0.0005

Probability of exploitation

0.15%

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	Versions
wazuh	wazuh	4.0.0 — 4.14.4

References

Advisories & Patches

https://github.com/wazuh/wazuh/security/advisories/GHSA-qvqj-p8mm-r7h3 https://github.com/wazuh/wazuh/security/advisories/GHSA-qvqj-p8mm-r7h3

Other References

https://github.com/wazuh/wazuh/releases/tag/v4.14.4

Frequently Asked Questions

What is CVE-2026-41499? +

Wazuh is a free and open source platform used for threat prevention, detection, and response. From version 4.0.0 to before version 4.14.4, multiple heap-based out-of-bounds WRITE vulnerabilities exist in parse_uname_string() (remoted_op.c). This function processes OS identification data from agents and contains a dangerous code pattern that appears in 4 locations within the same function: writing to strlen(ptr) - 1 without checking for empty strings. When the string is empty, strlen() returns 0, and 0 - 1 wraps to SIZE_MAX due to unsigned integer underflow. Due to pointer arithmetic wrapping, SIZE_MAX effectively becomes -1, causing a write exactly 1 byte before the allocated buffer. This corrupts heap metadata (e.g., the chunk size field in glibc malloc), leading to heap corruption. This issue has been patched in version 4.14.4. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-41499? +

CVE-2026-41499 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0005, placing it in the 0th percentile for exploitation probability.

What products are affected by CVE-2026-41499? +

CVE-2026-41499 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-2026-41499? +

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.

Related Vulnerabilities

CVE-2024-36343

Improper input validation in the System Management Mode (SMM) communications buffer could allow a privileged attacker to perform an out …

CVE-2026-44631 9.8

Buffer Underwrite vulnerability in Apache HTTP Server on crafted regular expressions in the configuration. This issue affects Apache HTTP Server: …

CVE-2023-25610 9.8

A buffer underwrite ('buffer underflow') vulnerability in the administrative interface of Fortinet FortiOS version 7.2.0 through 7.2.3, version 7.0.0 through …

CVE-2025-27439 8.5

Buffer underflow in some Zoom Workplace Apps may allow an authenticated user to conduct an escalation of privilege via network …

CVE-2025-27440 8.5

Heap overflow in some Zoom Workplace Apps may allow an authenticated user to conduct an escalation of privilege via network …

CVE-2026-34253 8.2

A buffer underflow vulnerability has been identified in the ogg123 utility from the vorbis-tools 1.4.3 package in function remotethread in …