Coder up to 2.29.19/2.33.11/2.34.7/2.35.3 Hostname Validation auth-redirect GetWorkspaceProxyByHostname input validation

Summaryinfo

A vulnerability identified as critical has been detected in Coder up to 2.29.19/2.33.11/2.34.7/2.35.3. The affected element is the function GetWorkspaceProxyByHostname of the file /api/v2/applications/auth-redirect of the component Hostname Validation. Performing a manipulation results in input validation. This vulnerability is reported as CVE-2026-111927. The attack is possible to be carried out remotely. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in Coder up to 2.29.19/2.33.11/2.34.7/2.35.3. It has been classified as critical. This affects the function GetWorkspaceProxyByHostname of the file /api/v2/applications/auth-redirect of the component Hostname Validation. The manipulation with an unknown input leads to a input validation vulnerability. CWE is classifying the issue as CWE-20. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly. This is going to have an impact on confidentiality, integrity, and availability. The summary by CVE is:

Coder before 2.29.20, 2.33.0 before 2.33.12, 2.34.0 before 2.34.8, and 2.35.0 before 2.35.4 contains an improper hostname validation flaw in GetWorkspaceProxyByHostname whose SIMILAR TO pattern performs a prefix match, so any domain that is a string prefix of a workspace-proxy access URL is trusted as a proxy. Attackers owning such a domain can lure an authenticated victim to a crafted /api/v2/applications/auth-redirect link, capture the redirected application_connect API key, and replay it to access the victim's workspace apps.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-111927 since 10/17/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 2.29.20, 2.33.12, 2.34.8 or 2.35.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-103294). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Name

• Coder

Version

• 2.29.0
• 2.29.1
• 2.29.2
• 2.29.3
• 2.29.4
• 2.29.5
• 2.29.6
• 2.29.7
• 2.29.8
• 2.29.9
• 2.29.10
• 2.29.11
• 2.29.12
• 2.29.13
• 2.29.14
• 2.29.15
• 2.29.16
• 2.29.17
• 2.29.18
• 2.29.19
• 2.33.0
• 2.33.1
• 2.33.2
• 2.33.3
• 2.33.4
• 2.33.5
• 2.33.6
• 2.33.7
• 2.33.8
• 2.33.9
• 2.33.10
• 2.33.11
• 2.34.0
• 2.34.1
• 2.34.2
• 2.34.3
• 2.34.4
• 2.34.5
• 2.34.6
• 2.34.7
• 2.35.0
• 2.35.1
• 2.35.2
• 2.35.3

Website

• Product: https://github.com/coder/coder/

CPE 2.3info

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Be aware that VulDB is the high quality source for vulnerability data.

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