CVE-2026-52100
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 · uneditedCross Site Request Forgery vulnerability in andreimarcu linux-server v.1.0 through v.2.3.8 allows a remote attacker to execute arbitrary code via the uploadPutHandler function
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 · moderate confidenceCross-Site Request Forgery vulnerability in the uploadPutHandler function of linux-server versions 1.0 through 2.3.8 allows remote attackers to trigger unauthorized file upload operations by tricking authenticated users into visiting malicious pages, potentially leading to arbitrary code execution if uploaded files are stored in the web root or lack proper validation.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
CVSS 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
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
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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Identify if linux-server is deployedCheck running processes, service configurations, or installed packages for the 'linux-server' product. Look for service names, binary paths, or application identifiers containing 'linux-server'.Affected if The system runs the linux-server product and the uploadPutHandler function is accessible.
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Determine linux-server versionRun 'linux-server --version', 'linux-server -v', or check installed package version (dpkg -l linux-server, rpm -qi linux-server, or similar). Compare the output against the affected range 1.0 to 2.3.8.Affected if The installed version is 1.0, 1.x, 2.x through 2.3.8 inclusive.
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Verify uploadPutHandler endpoint exists and is accessibleCheck application configuration files or routing definitions for the uploadPutHandler function/endpoint. If the web server or API is exposed, attempt a OPTIONS or GET request to the upload endpoint path (commonly /upload, /api/upload, or as defined in the application).Affected if The uploadPutHandler function is enabled and the upload endpoint is reachable over the network.
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Check upload storage locationInspect the server configuration or application code for the file upload storage path. Look for 'upload_dir', 'storage_path', 'web_root', or similar settings. Verify if uploaded files are stored within the publicly accessible web document root.Affected if Uploaded files are stored inside the web root directory, enabling the RCE impact if a malicious file is uploaded.
A user is affected if linux-server version 1.0 through 2.3.8 is running, the uploadPutHandler endpoint is exposed, and uploaded files can be served from the web root.
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.
From vendor dataImplement anti-CSRF tokens and SameSite cookie attributes for the upload endpoint, validate uploaded file types/content, store uploads outside the web root, and add origin/Referer header validation.
- Consultation3.0 h
- Implementation8.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-52100 — 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-2026-52100 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