CVE-2026-41499
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedWazuh 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.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceWazuh versions 4.0.0 to before 4.14.4 contain heap-based out-of-bounds write vulnerabilities in parse_uname_string() in remoted_op.c. The function writes to strlen(ptr) - 1 without validating that the string is non-empty. When processing an empty string, strlen() returns 0, and 0 - 1 wraps to SIZE_MAX due to unsigned integer underflow, causing a write 1 byte before the allocated buffer. This corrupts glibc malloc heap metadata, leading to heap corruption.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data>= 4.0.0, < 4.14.4CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check installed Wazuh versionRun the command to retrieve the Wazuh manager version, such as 'wazuh-control info' or check the package manager outputAffected if The version is 4.0.0 or higher but lower than 4.14.4
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Verify remoted component is activeCheck if the Wazuh remoted service is running, typically via 'systemctl status wazuh-manager' or by checking process list for remotedAffected if The remoted daemon is running and accepting connections from agents
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Confirm agent enrollment is enabledInspect the Wazuh manager configuration for agent enrollment settings, looking for <auth> or <enrollment> sections in ossec.confAffected if Agent enrollment or remote authentication is enabled, allowing agents to connect and send uname data to remoted
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Review remoted logs for anomalous writesExamine Wazuh manager logs for errors related to heap corruption, memory allocation failures, or crashes in the remoted process occurring around agent connection eventsAffected if Log entries indicate heap corruption, malloc failures, or remoted process instability after agent communications
You are affected if Wazuh manager version is between 4.0.0 and 4.14.3 inclusive AND the remoted component is actively accepting connections from agents that could send empty uname strings.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
dbcve · scoped4.14.4
Upgrade Wazuh to version 4.14.4 or later to patch the vulnerability. If immediate upgrade is not possible, consider restricting agent communications or network access to the remoted component as a compensating control.
4.14.4
- 1. Identify all Wazuh installations in the environment running version >= 4.0.0 and < 4.14.4 by checking the installed version (e.g., 'wazuh-control info' or package manager).
- 2. Review the Wazuh upgrade documentation for your deployment type (packages or sources) to understand the upgrade procedure.
- 3. Create a complete backup of the current Wazuh configuration, including ossec.conf, cluster.json, and any custom rules/decoders, stored in a secure location.
- 4. If running a Wazuh cluster, plan a coordinated upgrade starting with the master node followed by worker nodes, ensuring minimal service disruption.
- 5. Perform the upgrade to version 4.14.4 or the latest stable release using the appropriate method: for package installations, use the official Wazuh repository and upgrade commands; for source installations, download and compile the fixed version.
- 6. After upgrading, restart all Wazuh components (manager, agents, indexer, dashboard) in the correct order per the documentation.
- 7. Verify the fix by checking that the parse_uname_string() function in remoted_op.c has been patched (no longer contains the vulnerable strlen(ptr)-1 pattern without empty string checks).
- 8. Confirm the Wazuh manager is running correctly and agents can reconnect successfully.
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-41499 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2026-41499 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
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- Version or environment caveats, and links to real fixes
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