CyberSecBulletin
CVE-2026-3418NVD status: Deferred

WSO2 API Manager: Unrestricted Upload of File with Dangerous Type

Published Updated By the CyberSecBulletin desk

CVE-2026-3418 is a critical-severity unrestricted upload of file with dangerous type vulnerability in WSO2 API Manager from WSO2, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an attacker with administrator privileges, without any action from a user. The record lists versions 4.4.0.67, 4.5.0.52, 4.6.0.16 as the first without the flaw, so updating WSO2 API Manager to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.76% chance of exploitation within 30 days, higher than 56% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update WSO2 API Manager to 4.4.0.67 or 4.5.0.52 or 4.6.0.16, whichever matches your release line, or a later version.
  2. Update WSO2 Traffic Manager to 4.5.0.51 or 4.6.0.16, whichever matches your release line, or a later version.
  3. Update WSO2 API Control Plane to 4.5.0.53 or 4.6.0.17, whichever matches your release line, or a later version.
  4. Read the advisory on security.docs.wso2.com for workarounds and exact fixed builds.

Affected products and versions

VendorProductAffected versionsFixed in
WSO2WSO2 API Manager4.4.0 up to, but not including, 4.4.0.67; 4.5.0 up to, but not including, 4.5.0.52; 4.6.0 up to, but not including, 4.6.0.164.4.0.67, 4.5.0.52, 4.6.0.16
WSO2WSO2 Traffic Manager4.5.0 up to, but not including, 4.5.0.51; 4.6.0 up to, but not including, 4.6.0.164.5.0.51, 4.6.0.16
WSO2WSO2 API Control Plane4.5.0 up to, but not including, 4.5.0.53; 4.6.0 up to, but not including, 4.6.0.174.5.0.53, 4.6.0.17
WSO2WSO2 Universal Gateway4.5.0 up to, but not including, 4.5.0.52; 4.6.0 up to, but not including, 4.6.0.164.5.0.52, 4.6.0.16
WSO2WSO2 Carbon API Management Implementation9.30.67 up to, but not including, 9.30.67.156; 9.31.86 up to, but not including, 9.31.86.141; 9.32.147 up to, but not including, 9.32.147.449.30.67.156, 9.31.86.141, 9.32.147.44
WSO2WSO2 API Manager Publisher REST API V49.30.67 up to, but not including, 9.30.67.156; 9.31.86 up to, but not including, 9.31.86.141; 9.32.147 up to, but not including, 9.32.147.449.30.67.156, 9.31.86.141, 9.32.147.44
WSO2WSO2 Carbon API Management API9.30.67 up to, but not including, 9.30.67.1569.30.67.156

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
HighAdministrator-level access is required first.
User interaction
NoneNo action by a victim is required.
Scope
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H. Scored by CNA.

Official description

The System REST API accepts user-supplied file uploads without enforcing sufficient validation on the file type or destination, allowing files to be written to arbitrary server-accessible locations. Exploitation requires authenticated administrative access with publisher privileges. Successful exploitation permits an authenticated publisher to upload files to server-accessible locations. Depending on the deployment environment and how uploaded files are handled, this could lead to the execution of uploaded content, potentially resulting in remote code execution.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Unrestricted Upload of File with Dangerous Type

The product allows the upload or transfer of dangerous file types that are automatically processed within its environment.

How developers prevent this class of flaw

  • Generate a new, unique filename for an uploaded file instead of using the user-supplied filename, so that no external input is used at all.
  • When the set of acceptable objects, such as filenames or URLs, is limited or known, create a mapping from a set of fixed input values (such as numeric IDs) to the actual filenames or URLs, and reject all other inputs.
  • Consider storing the uploaded files outside of the web document root entirely. Then, use other mechanisms to deliver the files dynamically.

More Unrestricted Upload of File with Dangerous Type vulnerabilities (CWE-434)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in WSO2 API Manager

All WSO2 API Manager vulnerabilities

Recent Unrestricted Upload of File with Dangerous Type vulnerabilities

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