CVE-2026-46354

CRITICAL

Coder: PKCS#7 signature bypass in Azure instance identity allows unauthenticated agent token theft

Title source: cna
STIX 2.1

Description

Coder allows organizations to provision remote development environments via Terraform. In versions prior tp 2.24.5, 2.29.13, 2.30.8, 2.31.12, 2.32.2, and 2.33.3, `azureidentity.Validate()` verifies that the PKCS#7 signer certificate chains to a trusted Azure CA but never verifies the PKCS#7 signature itself. An attacker can embed a legitimate Azure certificate alongside arbitrary content e.g. `{"vmId":"<target>"}` and the forged `vmId` will be accepted returning the victim workspace agent's session token. No authentication is required. The attacker only needs to know a target VM's `vmId` which is a `UUIDv4`. That's a practical limitation which would typically require prior access to be exploited. Versions 2.24.5, 2.29.13, 2.30.8, 2.31.12, 2.32.2, and 2.33.3 patch the issue. As a workaround, reconfigure any Azure templates to use token authentication rather than `azure-instance-identity`.

References (8)

Core 8
Core References
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/pull/25286
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.24.5
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.29.13
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.30.8
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.31.12
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.32.2
X_Refsource_Misc x_refsource_misc
https://github.com/coder/coder/releases/tag/v2.33.3

Scores

CVSS v3 9.1
EPSS 0.0026
EPSS Percentile 17.7%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CISA SSVC

Vulnrichment
Exploitation none
Automatable yes
Technical Impact total

Details

CWE
CWE-347
Status published
Products (6)
coder/coder < 2.24.5 (2 CPE variants)
coder/coder >= 2.29.0, < 2.29.13
coder/coder >= 2.30.0, < 2.30.8
coder/coder >= 2.31.0, < 2.31.12
coder/coder >= 2.32.0-rc.0, < 2.32.2
coder/coder >= 2.33.0-rc.0, < 2.33.3
Published Jul 07, 2026
Tracked Since Jul 08, 2026