{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-33868","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-03-24T15:10:05.678Z","datePublished":"2026-03-27T19:50:07.687Z","dateUpdated":"2026-03-31T18:54:24.919Z"},"containers":{"cna":{"title":"Mastodon has a GET-Based Open Redirect via '/web/%2F<domain>'","problemTypes":[{"descriptions":[{"cweId":"CWE-601","lang":"en","description":"CWE-601: URL Redirection to Untrusted Site ('Open Redirect')","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/mastodon/mastodon/security/advisories/GHSA-xqw8-4j56-5hj6","tags":["x_refsource_CONFIRM"],"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-xqw8-4j56-5hj6"}],"affected":[{"vendor":"mastodon","product":"mastodon","versions":[{"version":">= 4.5.0, < 4.5.8","status":"affected"},{"version":">= 4.4.0, < 4.4.15","status":"affected"},{"version":"< 4.3.21","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-03-27T19:50:07.687Z"},"descriptions":[{"lang":"en","value":"Mastodon is a free, open-source social network server based on ActivityPub. Prior to versions 4.5.8, 4.4.15, and 4.3.21, an unauthenticated Open Redirect vulnerability (CWE-601) exists in the `/web/*` route due to improper handling of URL-encoded path segments. An attacker can craft a specially encoded URL that causes the application to redirect users to an arbitrary external domain, enabling phishing attacks and potential OAuth credential theft. The issue occurs because URL-encoded slashes (`%2F`) bypass Rails path normalization and are interpreted as host-relative redirects. Versions 4.5.8, 4.4.15, and 4.3.21 patch the issue."}],"source":{"advisory":"GHSA-xqw8-4j56-5hj6","discovery":"UNKNOWN"}},"adp":[{"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-31T18:50:44.597749Z","id":"CVE-2026-33868","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-03-31T18:54:24.919Z"}}]}}