{"id":"CVE-2026-104817","state":"PUBLISHED","title":"Misskey: Lack of rate limiting and size restrictions in RSS fetching API","description":"Misskey is an open source, federated social media platform. From 12.112.1 until 2026.7.0, the unauthenticated fetch-rss API lacks rate limiting and response-size restrictions and performs synchronous XML parsing. An attacker can trigger unbounded outbound HTTP requests and synchronous parsing, exhausting instance resources, amplifying requests toward third-party servers, or probing network-reachable services even when federation is disabled. This issue is fixed in version 2026.7.0.","publishedAt":"2026-10-13T18:39:30.169Z","updatedAt":"2026-10-13T19:04:03.012Z","severity":{"score":8.7,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:L/SI:N/SA:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["misskey-dev misskey"],"affected":[{"vendor":"misskey-dev","product":"misskey","versions":[{"version":">= 12.0.0, <= 13.14.2","status":"affected"},{"version":">= 2023.9.0-beta.1, < 2026.7.0","status":"affected"}]}],"references":["https://github.com/misskey-dev/misskey/security/advisories/GHSA-4x7v-qx8f-g3p8","https://github.com/misskey-dev/misskey/commit/a12ee2e5d72c40252e11a164b2231667c9697667","https://github.com/misskey-dev/misskey/releases/tag/2026.7.0"],"weaknesses":["CWE-405","CWE-770","CWE-918"],"ingestedAt":"2026-10-29T20:10:23.711Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/104xxx/CVE-2026-104817.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-104817","state":"PUBLISHED","datePublished":"2026-10-13T18:39:30.169Z","dateUpdated":"2026-10-13T19:04:03.012Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-10-02T14:17:09.334Z"},"containers":{"cna":{"title":"Misskey: Lack of rate limiting and size restrictions in RSS fetching API","descriptions":[{"lang":"en","value":"Misskey is an open source, federated social media platform. From 12.112.1 until 2026.7.0, the unauthenticated fetch-rss API lacks rate limiting and response-size restrictions and performs synchronous XML parsing. An attacker can trigger unbounded outbound HTTP requests and synchronous parsing, exhausting instance resources, amplifying requests toward third-party servers, or probing network-reachable services even when federation is disabled. This issue is fixed in version 2026.7.0."}],"affected":[{"vendor":"misskey-dev","product":"misskey","versions":[{"version":">= 12.0.0, <= 13.14.2","status":"affected"},{"version":">= 2023.9.0-beta.1, < 2026.7.0","status":"affected"}]}],"references":[{"url":"https://github.com/misskey-dev/misskey/security/advisories/GHSA-4x7v-qx8f-g3p8","name":"https://github.com/misskey-dev/misskey/security/advisories/GHSA-4x7v-qx8f-g3p8","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/misskey-dev/misskey/commit/a12ee2e5d72c40252e11a164b2231667c9697667","name":"https://github.com/misskey-dev/misskey/commit/a12ee2e5d72c40252e11a164b2231667c9697667","tags":["x_refsource_MISC"]},{"url":"https://github.com/misskey-dev/misskey/releases/tag/2026.7.0","name":"https://github.com/misskey-dev/misskey/releases/tag/2026.7.0","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"LOW","attackRequirements":"NONE","privilegesRequired":"NONE","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"HIGH","subConfidentialityImpact":"LOW","subIntegrityImpact":"NONE","subAvailabilityImpact":"LOW","baseScore":8.7,"baseSeverity":"HIGH","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:L/SI:N/SA:L","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-405","lang":"en","description":"CWE-405: Asymmetric Resource Consumption (Amplification)","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-770","lang":"en","description":"CWE-770: Allocation of Resources Without Limits or Throttling","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-918","lang":"en","description":"CWE-918: Server-Side Request Forgery (SSRF)","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-10-13T18:39:30.169Z"},"source":{"advisory":"GHSA-4x7v-qx8f-g3p8","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-10-13T19:03:52.462592Z","id":"CVE-2026-104817","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":"2026-10-13T19:04:03.012Z"}}]}}}