Executive brief
Coder, a platform for managing remote development environments, contains a flaw in its AI Bridge component. An authorized user could send a specially crafted, oversized request that exhausts the server's memory. This would cause the entire Coder control plane to crash, resulting in a total service outage for all users until the system is restarted.
Technical details
A resource exhaustion vulnerability (CWE-770) exists in Coder's AI Bridge provider handlers. The affected components used `io.ReadAll` to process incoming request bodies without enforcing a maximum size limit. An authenticated attacker with access to AI Bridge endpoints (such as `/api/v2/aibridge/anthropic/v1/messages`) can transmit an excessively large or chunked POST body, leading to heap memory exhaustion and an Out-Of-Memory (OOM) termination by the operating system. Because the AI Bridge runs in-process with `coderd`, this results in a complete denial of service for the API, workspace coordinator, and DERP relay. The issue is resolved in versions 2.33.8 and 2.34.2 by implementing `http.MaxBytesReader` to cap request sizes.
Affected products
- Coder Coder >= 2.33.0, < 2.33.8; >= 2.34.0, < 2.34.2
Timeline
- 2026-06-09: patched: Fix merged into main branch
- 2026-06-11: advisory: Security release versions 2.33.8 and 2.34.2 published
- 2026-07-07: disclosed: CVE-2026-55434 published to NVD