CVSS 3.1
6.8 mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:NCVE-2026-55438
Medium (6.8) in coder coder. EPSS 0.2% chance of exploitation in the next 30 days. Fixed in github.com/coder/coder/v2 2.29.17, 2.32.7, 2.33.8.
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.
Severity
- EPSS
- 0.2% chance of exploitation in the next 30 days; higher than 12% of CVEs (scores of 2026-10-31)
- CWE
- CWE-346
- Published
- Modified
- Record from
- the NVD, synced
Affected
- coder:coder
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-5wg6-jmq2-53pw | Go | github.com/coder/coder/v2 | >=2.34.0 <2.34.2 | 2.34.2 |
| GHSA-5wg6-jmq2-53pw | Go | github.com/coder/coder/v2 | >=2.33.0 <2.33.8 | 2.33.8 |
| GHSA-5wg6-jmq2-53pw | Go | github.com/coder/coder/v2 | >=2.30.0 <2.32.7 | 2.32.7 |
| GHSA-5wg6-jmq2-53pw | Go | github.com/coder/coder/v2 | <2.29.17 | 2.29.17 |
| GO-2026-5918 | Go | github.com/coder/coder | all versions | no fix published |
| GO-2026-5918 | Go | github.com/coder/coder/v2 | <2.29.17 >=2.30.0 <2.32.7 >=2.33.0 <2.33.8 >=2.34.0 <2.34.2 | 2.29.17, 2.32.7, 2.33.8, 2.34.2 |