CVE-2026-55429 Coder's workspace app upsert allows cross-workspace agent rebinding via user-controlled app ID

High 8.7 Published 8 Jul 2026 Updated 8 Jul 2026

Attackers with template author or provisioner access can rebind agents across workspaces by manipulating app IDs, bypassing authorization checks.

Exploited in the wild: Not known
Login needed: An administrator
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2026-55429?

CVE-2026-55429 is a high-severity missing authorization vulnerability in coder, published on 8 Jul 2026. An attacker needs administrator access to exploit it, with no action from the victim.

Official description

Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, `UpsertWorkspaceApp` overwrites an existing app's `agent_id` on a primary-key conflict and `insertAgentApp` accepts the app ID from the provisioner's `CompleteJob` payload without verifying it belongs to the workspace being built. `CompleteJob` runs under `dbauthz.AsProvisionerd` so the authorization layer does not block the cross-workspace upsert. Exploitation requires elevated access as a template author or external provisioner operator. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 verifies that any existing `workspace_apps` row matching the supplied ID belongs to the workspace being built and rejects cross-workspace agent reassignment. No known workarounds are available.

Weakness: CWE-639

Which versions are affected by CVE-2026-55429?

10 open source packages ship an affected version, including github.com/coder/coder/v2 and github.com/coder/coder. It affects 1 product.

Package	Affected	Fixed in
`github.com/coder/coder/v2` Go	All versions	`2.29.17, 2.32.7, 2.33.8, 2.34.2`
`github.com/coder/coder/v2` Go	All versions	`2.29.17`
`github.com/coder/coder/v2` Go	All versions	`2.29.17`
`github.com/coder/coder/v2` Go	From `2.30.0`	`2.32.7`
`github.com/coder/coder/v2` Go	From `2.30.0`	`2.32.7`
`github.com/coder/coder/v2` Go	From `2.33.0`	`2.33.8`

4 more packages

`github.com/coder/coder/v2` Go	From `2.33.0`	`2.33.8`
`github.com/coder/coder/v2` Go	From `2.34.0`	`2.34.2`
`github.com/coder/coder/v2` Go	From `2.34.0`	`2.34.2`
`github.com/coder/coder` Go	All versions	None

Products include Coder Coder.

How do I fix CVE-2026-55429?

Upgrade github.com/coder/coder/v2 to a fixed version for your release line: 2.29.17, 2.32.7, 2.33.8 or 2.34.2.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-55429 being exploited?

There is no known exploitation of CVE-2026-55429 in the wild and no public exploit code.

Sources

Also known as GHSA-9rjw-3gwp-f59v, GO-2026-5909.