GHSA-qrwj-vh9x-gw5v: Coder's workspace agent API insecure redirect handling allowed cross-agent file read and write
A vulnerability in Coder's workspace agent API allows a malicious workspace agent to redirect API requests to another agent on the tailnet, enabling unauthorized file read and write operations. Authenticated users controlling a modified agent can exploit this to access or modify files of other workspace users and potentially execute commands by chaining file writes with process-start requests. The issue arises from insecure handling of HTTP redirects and improper validation of the target host in API requests. The vulnerability affects multiple release lines prior to patched versions. No workarounds exist; upgrading to fixed versions is required.
AI Analysis
Technical Summary
The vulnerability stems from the workspace agent API client using the default HTTP client redirect behavior while dialing hosts based on the request URL's host if the port matches the workspace agent API port. Because agent tailnet IPs are deterministic from agent UUIDs, a malicious agent can craft redirects to another agent's tailnet IP, causing the client to send follow-up API requests to a victim agent instead of the intended one. Redirects that preserve method and body (HTTP 307, 308) enable replay of write and process-start requests, allowing cross-agent file read, write, and command execution as the victim workspace user. The fix disables automatic redirect following and enforces that API requests are only dialed to the intended agent's deterministic tailnet address, rejecting requests with mismatched hosts.
Potential Impact
An authenticated user with control over a modified workspace agent can redirect API requests to other agents on the tailnet, enabling unauthorized reading and writing of files as the victim workspace user. In versions exposing the process API, this can be escalated to command execution under the victim's user context, crossing workspace and tenant boundaries. This results in high confidentiality and integrity impact, with limited availability impact.
Mitigation Recommendations
Upgrading to the patched versions is required as no workarounds exist. The fix is included in versions 2.34.4, 2.33.10, 2.32.9, and 2.29.19 and later. The fix disables automatic HTTP redirect following for workspace agent API clients and enforces strict host validation to prevent redirect-based attacks.
GHSA-qrwj-vh9x-gw5v: Coder's workspace agent API insecure redirect handling allowed cross-agent file read and write
Description
A vulnerability in Coder's workspace agent API allows a malicious workspace agent to redirect API requests to another agent on the tailnet, enabling unauthorized file read and write operations. Authenticated users controlling a modified agent can exploit this to access or modify files of other workspace users and potentially execute commands by chaining file writes with process-start requests. The issue arises from insecure handling of HTTP redirects and improper validation of the target host in API requests. The vulnerability affects multiple release lines prior to patched versions. No workarounds exist; upgrading to fixed versions is required.
CVSS v3.1
Affected software
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability stems from the workspace agent API client using the default HTTP client redirect behavior while dialing hosts based on the request URL's host if the port matches the workspace agent API port. Because agent tailnet IPs are deterministic from agent UUIDs, a malicious agent can craft redirects to another agent's tailnet IP, causing the client to send follow-up API requests to a victim agent instead of the intended one. Redirects that preserve method and body (HTTP 307, 308) enable replay of write and process-start requests, allowing cross-agent file read, write, and command execution as the victim workspace user. The fix disables automatic redirect following and enforces that API requests are only dialed to the intended agent's deterministic tailnet address, rejecting requests with mismatched hosts.
Potential Impact
An authenticated user with control over a modified workspace agent can redirect API requests to other agents on the tailnet, enabling unauthorized reading and writing of files as the victim workspace user. In versions exposing the process API, this can be escalated to command execution under the victim's user context, crossing workspace and tenant boundaries. This results in high confidentiality and integrity impact, with limited availability impact.
Mitigation Recommendations
Upgrading to the patched versions is required as no workarounds exist. The fix is included in versions 2.34.4, 2.33.10, 2.32.9, and 2.29.19 and later. The fix disables automatic HTTP redirect following for workspace agent API clients and enforces strict host validation to prevent redirect-based attacks.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-qrwj-vh9x-gw5v
- Osv Schema Version
- 1.4.0
- Aliases
- []
- Ecosystems
- ["Go"]
- Database Specific Severity
- HIGH
- Cvss Version
- 3.1
Threat ID: 6a4c33f027e9c797195ec89b
Added to database: 07/06/2026, 23:02:08 UTC
Last enriched: 07/06/2026, 23:05:58 UTC
Last updated: 07/07/2026, 03:48:34 UTC
Views: 5
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