CVE-2026-26061
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 · uneditedFleet is open source device management software. Prior to 4.81.0, Fleet contained multiple unauthenticated HTTP endpoints that read request bodies without enforcing a size limit. An unauthenticated attacker could exploit this behavior by sending large or repeated HTTP payloads, causing excessive memory allocation and resulting in a denial-of-service (DoS) condition. Version 4.81.0 patches the issue.
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 confidenceFleet device management software versions prior to 4.81.0 contain unauthenticated HTTP endpoints that read request bodies without enforcing size limits, allowing attackers to send oversized or repeated payloads that exhaust memory and cause denial of service.
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< 4.81.0CVSS 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
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/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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Determine installed Fleet versionRun 'fleetctl --version' or check the Fleet service logs for the version string on startup, or query the Fleet API endpoint /api/fleet/version if accessibleAffected if The reported version is earlier than 4.81.0 (e.g., 4.80.0, 4.79.0, etc.)
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Verify Fleet HTTP service is runningCheck if the Fleet core service is active and listening on HTTP/HTTPS ports (typically port 8080 or 443) using commands like 'systemctl status fleet' or 'netstat -tlnp | grep fleet'Affected if The Fleet HTTP service is running and exposed to network traffic
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Confirm unauthenticated endpoints are reachableSend a test HTTP request to common unauthenticated Fleet endpoints such as /api/fleet/login or /api/fleet/setup without providing credentials, and verify the server accepts and processes the requestAffected if The server accepts and processes requests to unauthenticated endpoints without rejecting them
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Check for abnormal memory usageMonitor the Fleet service process memory consumption over time using tools like 'top', 'htop', or 'ps aux | grep fleet' to identify unusual growthAffected if Memory usage is continuously growing or已达到 unusually high levels without legitimate cause
You are affected if Fleet version is below 4.81.0 and the HTTP service is exposed, allowing unauthenticated attackers to send oversized payloads that could exhaust server memory.
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 · scoped4.81.0
Upgrade Fleet to version 4.81.0 or later to patch the vulnerability.
Fleet version 4.81.0
- 1. Backup your current Fleet database and configuration files before proceeding with the upgrade
- 2. Review the Fleet 4.81.0 release notes for any migration requirements or configuration changes
- 3. Test the upgrade in a non-production environment first to ensure compatibility with your existing setup
- 4. Upgrade your Fleet installation to version 4.81.0 using your deployment method (e.g., helm upgrade, docker, or package manager)
- 5. Verify the upgrade was successful by checking the Fleet version and ensuring all services start correctly
- 6. Monitor system resources and logs to confirm the DoS vulnerability has been remediated
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation1.0 h
- Implementation2.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,904.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-26061 — 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-2026-26061 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
No notes yet
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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
- No spam, self-promotion, credentials, or personal data