High severity · published Oct 17, 2026
CVE-2026-111927
Coder before 2.35.4 Credential Theft via Workspace Proxy Hostname Prefix Match
7.7
CVSS
0.2%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:N
Attack vector
Network
Complexity
High
Privileges
Low
User interaction
Required
Confidentiality
High
Integrity
High
Availability
None
Scope
Changed
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 10% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CO
coder · coder
2.35.0 before 2.35.4; 2.34.0 before 2.34.8; 2.33.0 before 2.33.12; before 2.29.20 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-111927
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-111927
github.com
https://github.com/coder/coder/security/advisories/GHSA-h58h-qvv5-xvwg
www.vulncheck.com
https://www.vulncheck.com/advisories/coder-before-2.35.4-credential-theft-via-workspace-proxy-hostname-prefix-match
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