{"id":"CVE-2026-101090","title":"Nezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect endpoint","summary":"Nezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect endpoint. When the new optional dashboard_host setting is empty, /api/v1/oauth2/{provider} (cmd/dashboard/controller/oauth2.go) reflects the attacker-supplied…","severity":"critical","cvss":9.8,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-601"],"vendor":"nezhahq","product":"nezha","affected":["nezha >= 2.2.3 <= 2.2.3"],"published":"2026-09-27","updated":"2026-09-27","sourceUpdated":"2026-09-27T21:17:03.003","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-101090","references":[{"url":"https://github.com/nezhahq/nezha/security/advisories/GHSA-rf68-8gjr-36q7","label":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/nezha-through-2.2.3-host-header-injection-via-oauth2-redirect-uri","label":"disclosure@vulncheck.com"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-27T20:58:01.538Z","slug":"CVE-2026-101090","body":"## Overview\n\nNezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect endpoint. When the new optional dashboard_host setting is empty, /api/v1/oauth2/{provider} (cmd/dashboard/controller/oauth2.go) reflects the attacker-supplied HTTP Host header into the redirect_uri sent to the identity provider instead of falling back to the configured install_host. An attacker who induces a victim to begin OAuth2 login via a request that reaches Nezha with a forged Host header can cause an attacker-controlled callback URL to be used as the redirect_uri; if the OAuth2 provider accepts it, the victim's authorization code is delivered to the attacker origin, allowing the attacker to complete the OAuth2 login/binding flow and take over the account. This regresses the fix for GHSA-9rc6-8cjv-rcvx and is configuration-dependent (dashboard_host empty). At the time of the advisory no patched version was available.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":54,"depthScoreParts":{"impact":53.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}