CVE-2026-63443
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure, data tampering.
- Exploit odds
- 0.8% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.8% in the next 30 days (EPSS).
- Severity: 8.3 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.8% · EPSS, next 30 days
- Weakness
- CWE-863 · Incorrect authorization
- Record status
- Awaiting Analysis
Attack profile CVSS 3.1 · 8.3
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- Low
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-63443.md and follow it. Check whether this project is affected by CVE-2026-63443. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- 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
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