{"id":"CVE-2026-41259","state":"PUBLISHED","title":"Mastodon: Insufficient verification of email addresses","description":"Mastodon is a free, open-source social network server based on ActivityPub. Prior to v4.5.9, v4.4.16, and v4.3.22, Mastodon allows restricting new user sign-up based on e-mail domain names, and performs basic validation on e-mail addresses, but fails to restrict characters that are interpreted differently by some mailing servers. This vulnerability is fixed in v4.5.9, v4.4.16, and v4.3.22.","publishedAt":"2026-04-23T18:55:20.854Z","updatedAt":"2026-04-23T19:24:15.567Z","severity":{"score":8.2,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","source":"GitHub_M"},"assigner":"GitHub_M","products":["mastodon mastodon"],"affected":[{"vendor":"mastodon","product":"mastodon","versions":[{"version":"< 4.3.22","status":"affected"},{"version":">= 4.4.0-beta.1, < 4.4.16","status":"affected"},{"version":">= 4.5.0-beta.1, < 4.5.9","status":"affected"}]}],"references":["https://github.com/mastodon/mastodon/security/advisories/GHSA-5r37-qpwq-2jhh"],"weaknesses":["CWE-841"],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/41xxx/CVE-2026-41259.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-41259","state":"PUBLISHED","datePublished":"2026-04-23T18:55:20.854Z","dateUpdated":"2026-04-23T19:24:15.567Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-04-18T14:01:46.801Z"},"containers":{"cna":{"title":"Mastodon: Insufficient verification of email addresses","descriptions":[{"lang":"en","value":"Mastodon is a free, open-source social network server based on ActivityPub. Prior to v4.5.9, v4.4.16, and v4.3.22, Mastodon allows restricting new user sign-up based on e-mail domain names, and performs basic validation on e-mail addresses, but fails to restrict characters that are interpreted differently by some mailing servers. This vulnerability is fixed in v4.5.9, v4.4.16, and v4.3.22."}],"affected":[{"vendor":"mastodon","product":"mastodon","versions":[{"version":"< 4.3.22","status":"affected"},{"version":">= 4.4.0-beta.1, < 4.4.16","status":"affected"},{"version":">= 4.5.0-beta.1, < 4.5.9","status":"affected"}]}],"references":[{"url":"https://github.com/mastodon/mastodon/security/advisories/GHSA-5r37-qpwq-2jhh","name":"https://github.com/mastodon/mastodon/security/advisories/GHSA-5r37-qpwq-2jhh","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"PRESENT","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"HIGH","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","subAvailabilityImpact":"NONE","baseScore":8.2,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-841","lang":"en","description":"CWE-841: Improper Enforcement of Behavioral Workflow","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-04-23T18:55:20.854Z"},"source":{"advisory":"GHSA-5r37-qpwq-2jhh","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-04-23T19:23:56.034984Z","id":"CVE-2026-41259","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":"2026-04-23T19:24:15.567Z"}}]}}}