{"id":"CVE-2026-46349","state":"PUBLISHED","title":"Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring","description":"Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon's normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain class of spoofing, allowing attackers to re-arrange a valid signed JSON-LD activity from a third-party actor to have it processed differently. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23.","publishedAt":"2026-06-24T19:40:35.022Z","updatedAt":"2026-06-25T13:16:49.851Z","severity":{"score":5.3,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["mastodon mastodon"],"affected":[{"vendor":"mastodon","product":"mastodon","versions":[{"version":">= 4.5.0-beta.1, < 4.5.10","status":"affected"}]}],"references":["https://github.com/mastodon/mastodon/security/advisories/GHSA-chgx-jx3p-rf73"],"weaknesses":["CWE-347"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/46xxx/CVE-2026-46349.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46349","state":"PUBLISHED","datePublished":"2026-06-24T19:40:35.022Z","dateUpdated":"2026-06-25T13:16:49.851Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-13T18:37:30.990Z"},"containers":{"cna":{"title":"Mastodon: LD-Signature Bypass via JSON-LD Named-Graph Restructuring","descriptions":[{"lang":"en","value":"Mastodon is a free, open-source social network server based on ActivityPub. Prior to 4.5.10, 4.4.17, and 4.3.23, Mastodon's normalization of incoming activities signed with Linked-Data Signatures does not sufficiently protect the activities from a certain class of spoofing, allowing attackers to re-arrange a valid signed JSON-LD activity from a third-party actor to have it processed differently. This vulnerability is fixed in 4.5.10, 4.4.17, and 4.3.23."}],"affected":[{"vendor":"mastodon","product":"mastodon","versions":[{"version":">= 4.5.0-beta.1, < 4.5.10","status":"affected"}]}],"references":[{"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-chgx-jx3p-rf73","name":"https://github.com/mastodon/mastodon/security/advisories/GHSA-chgx-jx3p-rf73","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":5.3,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-347","lang":"en","description":"CWE-347: Improper Verification of Cryptographic Signature","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-06-24T19:40:35.022Z"},"source":{"advisory":"GHSA-chgx-jx3p-rf73","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-25T13:16:40.328930Z","id":"CVE-2026-46349","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-25T13:16:49.851Z"}}]}}}