CVE-2026-63443
Description
Coder allows organizations to provision remote development environments via Terraform. Prior to 2.29.19, 2.32.9, 2.33.10, and 2.34.4, agentConn.apiClient() follows redirects while its custom transport accepts the host from the redirected request URL when the port is the workspace agent HTTP API port 4. An authenticated user who controls a modified workspace agent and knows another online agent's UUID can derive the victim's tailnet address and redirect control-plane requests to that agent. HTTP 301, 302, and 303 redirects can redirect read requests, while HTTP 307 and 308 preserve replayable write and process-start requests. The redirected workspace agent file APIs can read or write files as the victim workspace user, and affected versions exposing the workspace agent process API can execute commands after a redirected file write, crossing workspace and tenant boundaries. This issue is fixed in versions 2.29.19, 2.32.9, 2.33.10, and 2.34.4.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://github.com/coder/coder/commit/2312b67bc52c4e314c18c4b4be5dcf5500c94ad7
- https://github.com/coder/coder/commit/812549d671d0f5a0b45adcee860d37b70aaddccd
- https://github.com/coder/coder/commit/ec3ba84c0002f47dd979c073cde1ab345acbaea5
- https://github.com/coder/coder/commit/eeb2624549ddb85538e493af3e678fdb185a809f
- https://github.com/coder/coder/commit/f8bdec5add4711650d5bfb6ff93d0cc9d7821c81
- https://github.com/coder/coder/pull/26600
- https://github.com/coder/coder/pull/26611
- https://github.com/coder/coder/pull/26612
- https://github.com/coder/coder/pull/26613
- https://github.com/coder/coder/pull/26622
- https://github.com/coder/coder/releases/tag/v2.29.19
- https://github.com/coder/coder/releases/tag/v2.32.9
- https://github.com/coder/coder/releases/tag/v2.33.10
- https://github.com/coder/coder/releases/tag/v2.34.4
- https://github.com/coder/coder/security/advisories/GHSA-qrwj-vh9x-gw5v
CWEs
CWE-863 CWE-918
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.