Key points
- The vulnerability allows unauthenticated clients to control ImageMagick convert arguments.
- Affected versions include 8.0.1 through 8.1.11, 9.0.0 through 9.2.15, and 10.0.0 through 10.2.0.
- Users are recommended to upgrade to versions 9.2.16, 10.1.5, or 10.2.1.
The National Vulnerability Database records that Apache Traffic Server’s experimental magick plugin allows an unauthenticated client to control ImageMagick convert arguments. This occurs in the default unsigned configuration. The issue is classified as CWE-88 and carries a CVSS base score of 10.0. This high severity rating reflects the lack of authentication required to exploit the weakness. Systems running the affected software with default settings are exposed to direct argument manipulation by external clients.
By the numbers
- CVSS score of 10.0 for CVE-2026-111813 indicates critical severity.
- Three major version branches are affected: 8.x, 9.x, and 10.x.
- Three versions are recommended for upgrade: 9.2.16, 10.1.5, and 10.2.1.
What the figures mean
The perfect CVSS score reflects the ease with which an attacker can exploit this vulnerability without any prior authentication. Because the default configuration of the magick plugin does not require signed requests, any network-accessible instance using the default settings is exposed to direct argument manipulation. This means an attacker can send crafted requests that inject malicious arguments into the ImageMagick convert command. The source material does not specify further consequences beyond the control of these arguments.
What to watch
Organizations using Apache Traffic Server should immediately audit their environments for the presence of the experimental magick plugin. Teams need to verify whether their deployments are using the default unsigned configuration, as this is the primary vector for exploitation. Monitoring network logs for unusual ImageMagick convert arguments can help detect active exploitation attempts. Additionally, administrators should review access controls to ensure that sensitive plugins are not exposed to untrusted networks.
Infection and persistence in general
Teams usually encounter this category of vulnerability when experimental or optional modules are enabled with permissive default settings. Attackers often target these components because they bypass standard authentication checks, allowing direct interaction with underlying system utilities. Analysts typically examine server logs for anomalous command-line arguments passed to image processing tools. Persistence mechanisms are rarely inherent in the vulnerability itself; instead, attackers leverage the initial access to deploy secondary payloads, which then maintain long-term access to the compromised system for further lateral movement.
What to do and how to stay safe: Apache Traffic Server
- Identify all instances of Apache Traffic Server running the magick plugin and verify their configuration status.
- Upgrade affected servers to version 9.2.16, 10.1.5, or 10.2.1 as recommended by the vendor.
- Restrict network access to the magick plugin endpoints to trusted sources only if immediate patching is not possible.
- Monitor system processes for unexpected executions of image conversion utilities triggered by web requests.
Step-by-step guide: Patch Management Implementation: A Step-by-Step Rollout Plan
General security guidance from the Sandbox Gazette newsroom. It is not confirmed advice from the organisations named in this story.
Frequently asked questions
Which Apache Traffic Server versions are vulnerable to CVE-2026-111813?
Versions 8.0.1 through 8.1.11, 9.0.0 through 9.2.15, 10.0.0 through 10.1.4, and 10.2.0 are affected.
Is there a patch available for this critical vulnerability?
Users are recommended to upgrade to version 9.2.16, 10.1.5, or 10.2.1 to fix the issue.
What type of weakness is classified as CVE-2026-111813?
It is an argument injection weakness classified under CWE-88, allowing unauthenticated control of ImageMagick arguments.
