Old Docker authorization bypass pops up despite previous patch
Summary
A new vulnerability (CVE-2026-34040, rated 8.8 on the CVSS score, a 0-10 severity rating) allows attackers to bypass authorization plug-ins (add-on security tools that control who can run Docker commands) in Docker Engine and gain root-level access to host systems. The flaw exploits the same underlying problem discovered in 2016, where oversized API requests (over 1MB) are silently dropped before the authorization plug-in can inspect them, causing the plug-in to approve requests it cannot see, which Docker then executes in full.
Solution / Mitigation
Update to Docker Engine 29.3.1 or Docker Desktop 4.66.1. If immediate updates cannot be deployed, route API requests through a reverse proxy that blocks all requests over 512KB as a temporary mitigation. Additionally, administrators can search daemon logs using 'journalctl -u docker | grep "Request body is larger than"' to detect potential exploitation attempts.
Classification
Related Issues
Original source: https://www.csoonline.com/article/4157405/old-docker-authorization-bypass-pops-up-despite-previous-patch.html
First tracked: April 10, 2026 at 08:00 PM
Classified by LLM (prompt v3) · confidence: 72%