{"id":"CVE-2026-101090","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-101090","generatedAt":"2026-10-28T01:46:53.442Z","title":"Nezha 2.2.3 contains a Host header injection regression in the OAuth2 redirect endpoint.","description":"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.","published":"2026-09-27T21:17:03.000Z","lastModified":"2026-09-28T21:02:16.000Z","status":"Deferred","sourceIdentifier":"disclosure@vulncheck.com","cvss":{"version":"4.0","score":9.3,"severity":"CRITICAL","vector":"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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-601"],"affected":[],"epss":{"score":0.00443,"percentile":0.38295,"date":"2026-10-26","history":[{"date":"2026-09-28","score":0.00358,"percentile":0.2703}]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.44%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[{"kind":"new","label":"New CVE","at":"2026-09-27T21:17:03.000Z","detail":{"score":"9.3","severity":"CRITICAL","publishedAt":"2026-09-27T21:17:03.003Z"},"summary":"New CVE, critical severity (CVSS 9.3)."}],"references":[{"url":"https://github.com/nezhahq/nezha/security/advisories/GHSA-rf68-8gjr-36q7","source":"disclosure@vulncheck.com"},{"url":"https://www.vulncheck.com/advisories/nezha-through-2.2.3-host-header-injection-via-oauth2-redirect-uri","source":"disclosure@vulncheck.com"},{"url":"https://github.com/nezhahq/nezha/security/advisories/GHSA-rf68-8gjr-36q7","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-101090","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}