{"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": "2026-03-27T19:50:07.687Z"}, "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"}}}}

{}

{"cveTags": [], "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."}], "id": "CVE-2026-33868", "lastModified": "2026-03-27T20:16:34.333", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-03-27T20:16:34.333", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/mastodon/mastodon/security/advisories/GHSA-xqw8-4j56-5hj6"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-601"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}