CVE-2026-55438

5.8 MEDIUM
Published: July 08, 2026 Modified: July 08, 2026
View on NVD

Description

Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2, Coder's subdomain-based workspace app proxy allowed the same-owner CORS check to be bypassed. When a workspace-name subdomain segment parsed as a UUID, the workspace was resolved by ID without confirming the URL's username matched the real owner, while the CORS middleware trusted the unverified username in the hostname. Practical exploitation requires subdomain app routing (wildcard hostname) enabled and a victim who visits the attacker's crafted app URL while authenticated. The fix in versions 2.29.17, 2.32.7, 2.33.8, and 2.34.2 validates the subdomain username against the resolved workspace's actual owner and bases the same-owner CORS decision on the authoritative owner identity. No known workarounds are available.

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CVSS v3.x Details

0.0 Low Medium High Critical 10.0
Vector String
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N

References to Advisories, Solutions, and Tools

Patch Vendor Advisory Exploit Third Party Advisory
https://github.com/coder/coder/pull/26085
Source: security-advisories@github.com
https://github.com/coder/coder/pull/26086
Source: security-advisories@github.com
https://github.com/coder/coder/releases/tag/v2.29.17
Source: security-advisories@github.com
https://github.com/coder/coder/releases/tag/v2.32.7
Source: security-advisories@github.com
https://github.com/coder/coder/releases/tag/v2.33.8
Source: security-advisories@github.com
https://github.com/coder/coder/releases/tag/v2.34.2
Source: security-advisories@github.com

7 reference(s) from NVD

Quick Stats

CVSS v3 Score
5.8 / 10.0
Exploitation Status
Not in CISA KEV

Weaknesses (CWE)