CVE-2026-126308

Coder 2.38.0 before 2.38.2 Session Token Leak via Sub-Agent External Apps

Published Nov 13, 2026 CVSS 4.0 · 8.7 High EPSS n/a KEV · Not listed

Description

The web dashboard in Coder 2.24.0 before 2.29.23, 2.30.0 before 2.34.14, 2.35.0 before 2.36.9, 2.37.0 before 2.37.6, and 2.38.0 before 2.38.2 replaces the $SESSION_TOKEN placeholder in external app URLs with a full-access API key without checking whether the app belongs to a sub-agent. Code running in a workspace can register a disguised sub-agent app with a custom protocol URL, so the owner's click sends their API key to an attacker-chosen destination.

Affected Products

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

coder

unaffected

Version	Status	Constraints
`2.38.0`	affected	< 2.38.2
`2.38.2`	unaffected	—

coder

unaffected

Version	Status	Constraints
`2.37.0`	affected	< 2.37.6
`2.37.6`	unaffected	—

coder

unaffected

Version	Status	Constraints
`2.36.0`	affected	< 2.36.9
`2.36.9`	unaffected	—

coder

unaffected

Version	Status	Constraints
`2.30.0`	affected	< 2.34.14
`2.34.14`	unaffected	—

coder

unaffected

Version	Status	Constraints
`2.24.0`	affected	< 2.29.23
`2.29.23`	unaffected	—

coder

unaffected

Version	Status	Constraints
`2.35.0`	affected	< 2.36.0
`2.36.0`	unaffected	—

No data.

No data available yet.

Remediation

No solution or workaround provided in the CVE record

Tracking

Advisories

No advisories available

Metrics

Attack Vector Network

Attack Complexity High

Privileges Required Low

Attack Requirements Present

User Interaction Passive

Vulnerable System Confidentiality Impact High

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact High

Subsequent System Integrity Impact High

Subsequent System Availability Impact None

Attack Vector Network

Attack Complexity High

Privileges Required Low

Scope Changed

Confidentiality Impact High

Integrity Impact High

Availability Impact None

User Interaction Required

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

No EPSS score available.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://github.com/coder/coder/security/advisories/GHSA-2x8w-q434-f76p
https://www.vulncheck.com/advisories/coder-2.38.0-before-2.38.2-session-token-leak-via-sub-agent-external-apps

History

Nov 13, 2026 9:45 AM Description updated. Title updated. First appearance in the feed. Weaknesses updated. Affected versions updated. Affected vendors updated. Added references. Scoring metrics updated View changes

Type	Values Removed	Values Added
Description		The web dashboard in Coder 2.24.0 before 2.29.23, 2.30.0 before 2.34.14, 2.35.0 before 2.36.9, 2.37.0 before 2.37.6, and 2.38.0 before 2.38.2 replaces the $SESSION_TOKEN placeholder in external app URLs with a full-access API key without checking whether the app belongs to a sub-agent. Code running in a workspace can register a disguised sub-agent app with a custom protocol URL, so the owner's click sends their API key to an attacker-chosen destination.
Title		Coder 2.38.0 before 2.38.2 Session Token Leak via Sub-Agent External Apps
First Time appeared		Coder Coder coder
Weaknesses		CWE-201
CPEs		cpe:2.3:a:coder:coder::::::::
Vendors & Products		Coder Coder coder
References		https://github.com/coder/coder/security/advisories/GHSA-2x8w-q434-f76p https://www.vulncheck.com/advisories/coder-2.38.0-before-2.38.2-session-token-leak-via-sub-agent-external-apps
Metrics		cvssV3_1 `{'score': 7.7, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N'}` cvssV4_0 `{'score': 8.7, 'vector': 'CVSS:4.0/AV:N/AC:H/AT:P/PR:L/UI:P/VC:H/VI:H/VA:N/SC:H/SI:H/SA:N'}`