GHSA-wrq8-fcv5-8hvp

Source

https://github.com/advisories/GHSA-wrq8-fcv5-8hvp

Import Source

https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-wrq8-fcv5-8hvp/GHSA-wrq8-fcv5-8hvp.json

JSON Data

https://api.osv.dev/v1/vulns/GHSA-wrq8-fcv5-8hvp

Aliases

Published

2026-07-06T20:58:30Z

Modified

2026-07-07T16:11:26Z

Severity

8.2 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:N CVSS Calculator

Summary

Coder: Route hijacking through lack of validation of agent-supplied AllowedIPs in tailnet coordinator

Details

Summary

The tailnet coordinator validates that an agent's Addresses derive from its authenticated UUID but applies no equivalent check to AllowedIPs. The coordinator forwards agent-supplied AllowedIPs verbatim to tunnel peers which install them into the WireGuard peer configuration.

Impact

A malicious workspace agent can advertise arbitrary AllowedIPs prefixes including another agent's tailnet address. Coder's ServerTailnet routes to agents by tailnet IP so an agent that claims a victim's prefix can intercept web terminal and workspace app traffic and serve spoofed content. Exploitation requires an authenticated user with a running workspace and a modified agent binary.

Patches

The fix validates each AllowedIPs prefix against the authenticating agent's UUID just like Addresses.

The fix was backported to all supported release lines:

Release line	Patched version
2.34	v2.34.2
2.33	v2.33.8
2.32	v2.32.7
2.29 (ESR)	v2.29.17

Workarounds

Operators who cannot upgrade immediately should monitor coordinator logs for agents advertising unexpected AllowedIPs prefixes.

Resources

Fix: #26144

Credits

Coder would like to thank Anthropic's Security Team (ANT-2026-22451) for independently disclosing this issue!

Database specific

{
    "cwe_ids":  [
        "CWE-285",
        "CWE-863"
    ],
    "github_reviewed":  true,
    "github_reviewed_at":  "2026-07-06T20:58:30Z",
    "nvd_published_at":  null,
    "severity":  "HIGH"
}

References

Affected packages

Go / github.com/coder/coder/v2

Package

Name: github.com/coder/coder/v2; View open source insights on deps.dev
Purl: pkg:golang/github.com/coder/coder/v2

Affected ranges

Type: SEMVER
Events: Introduced

2.34.0

Fixed

2.34.2

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-wrq8-fcv5-8hvp/GHSA-wrq8-fcv5-8hvp.json"

Go / github.com/coder/coder/v2

Package

Name: github.com/coder/coder/v2; View open source insights on deps.dev
Purl: pkg:golang/github.com/coder/coder/v2

Affected ranges

Type: SEMVER
Events: Introduced

2.33.0

Fixed

2.33.8

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-wrq8-fcv5-8hvp/GHSA-wrq8-fcv5-8hvp.json"

Go / github.com/coder/coder/v2

Package

Name: github.com/coder/coder/v2; View open source insights on deps.dev
Purl: pkg:golang/github.com/coder/coder/v2

Affected ranges

Type: SEMVER
Events: Introduced

2.30.0

Fixed

2.32.7

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-wrq8-fcv5-8hvp/GHSA-wrq8-fcv5-8hvp.json"

Go / github.com/coder/coder/v2

Package

Name: github.com/coder/coder/v2; View open source insights on deps.dev
Purl: pkg:golang/github.com/coder/coder/v2

Affected ranges

Type: SEMVER
Events: Introduced

0 Unknown introduced version / All previous versions are affected

Fixed

2.29.17

Database specific

source

"https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/07/GHSA-wrq8-fcv5-8hvp/GHSA-wrq8-fcv5-8hvp.json"