CVE-2026-4191
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 · uneditedA flaw has been found in JawherKl node-api-postgres up to 2.5. Affected is the function path.extname of the file index.js of the component Profile Picture Handler. This manipulation causes unrestricted upload. The attack is possible to be carried out remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
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 confidenceThe Profile Picture Handler in JawherKl node-api-postgres up to v2.5 uses path.extname() to validate uploaded files, which can be easily bypassed using double extensions (e.g., avatar.php.jpg) or by manipulating the filename. This allows attackers to upload executable files to the server, leading to remote code execution.
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
- Low
- Integrity
- Low
- Availability
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L
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.
-
Identify the installed version of node-api-postgresCheck the package.json file in the project root for the version of the 'node-api-postgres' dependency, or run 'npm list node-api-postgres' to see the installed versionAffected if The version is 2.5 or lower, or if no specific version is listed (implying an unpatched release)
-
Locate the profile picture upload handlerSearch the codebase for files handling profile picture uploads; look for routes or controllers containing 'avatar', 'profile', 'upload', or 'picture' in the filename or handler nameAffected if The upload handler exists and processes user-submitted files for profile pictures
-
Examine the file validation logic in the upload handlerOpen the upload handler file and inspect the code that validates uploaded files; look for path.extname() being used to check file extensionsAffected if The code uses path.extname() alone to validate file types without additional content-type or magic-byte verification
-
Check how uploaded files are storedFind the code that moves or saves uploaded files; determine the destination directory and whether it is inside or outside the webrootAffected if Uploaded files are stored in a publicly accessible webroot directory with the original or predictable filenames
-
Verify if extension allowlisting is enforcedReview the upload validation logic to see if it uses a whitelist of permitted extensions (e.g., only .jpg, .png, .gif) rather than relying on extension extraction via path.extname()Affected if The validation does not use a strict allowlist or does not combine extension checking with content-type/magic-byte verification
You are affected if you are running node-api-postgres v2.5 or lower and the profile picture upload handler relies solely on path.extname() for file validation without additional content verification or strict allowlisting.
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 dataReplace extension-based validation with whitelist filtering AND content-type/magic-byte verification; store uploads outside the webroot with randomized filenames; implement strict allowlist for permitted file types for profile pictures.
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 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 $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2026-4191 — 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-2026-4191 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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