CVE-2026-111927: Coder before 2.35.4 Credential Theft via Workspace Proxy Hostname Prefix Match

Severity: high (CVSS 7.7 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-17 · updated 2026-10-21
Weakness: CWE-522

Description

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.

Affected products

coder: from 2.35.0 before 2.35.4; from 2.34.0 before 2.34.8; from 2.33.0 before 2.33.12; before 2.29.20 — fixed in 2.29.20, 2.33.12, 2.34.8, 2.35.4

How to fix

Upgrade to a fixed version: coder 2.29.20, 2.33.12, 2.34.8, 2.35.4. Check the vendor advisory for mitigations.

References

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