{"id":"CVE-2026-101090","summary":"Nezha through 2.2.3 Host Header Injection via OAuth2 redirect_uri","details":"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 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.","aliases":["GHSA-rf68-8gjr-36q7","GO-2026-6486"],"modified":"2026-09-29T03:31:03.158529469Z","published":"2026-09-27T20:50:00.857Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101090.json","cna_assigner":"VulnCheck","cwe_ids":["CWE-601"]},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/101xxx/CVE-2026-101090.json"},{"type":"ADVISORY","url":"https://github.com/nezhahq/nezha/security/advisories/GHSA-rf68-8gjr-36q7"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-101090"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/nezha-through-2.2.3-host-header-injection-via-oauth2-redirect-uri"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/nezhahq/nezha","events":[{"introduced":"3d74cd9431a48fa89c6489689eac82a872799ea0"},{"last_affected":"3d74cd9431a48fa89c6489689eac82a872799ea0"}],"database_specific":{"extracted_events":[{"introduced":"2.2.3"},{"last_affected":"2.2.3"}],"source":"AFFECTED_FIELD"}}],"versions":["2.2.3","v2.2.3"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-101090.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"}]}