{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-46431","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","state":"PUBLISHED","assignerShortName":"GitHub_M","dateReserved":"2026-05-13T22:18:22.830Z","datePublished":"2026-05-26T16:42:40.675Z","dateUpdated":"2026-05-26T17:39:14.529Z"},"containers":{"cna":{"title":"Algernon: Auto-refresh SSE event server sets Access-Control-Allow-Origin: *","problemTypes":[{"descriptions":[{"cweId":"CWE-942","lang":"en","description":"CWE-942: Permissive Cross-domain Policy with Untrusted Domains","type":"CWE"}]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":4.3,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N","version":"3.1"}}],"references":[{"name":"https://github.com/xyproto/algernon/security/advisories/GHSA-hw27-4v2q-5qff","tags":["x_refsource_CONFIRM"],"url":"https://github.com/xyproto/algernon/security/advisories/GHSA-hw27-4v2q-5qff"}],"affected":[{"vendor":"xyproto","product":"algernon","versions":[{"version":"< 1.17.7","status":"affected"}]}],"providerMetadata":{"orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M","dateUpdated":"2026-05-26T16:42:40.675Z"},"descriptions":[{"lang":"en","value":"Algernon is a small self-contained pure-Go web server. Prior to 1.17.7, the SSE event server's Access-Control-Allow-Origin response header was hardcoded to the wildcard * regardless of the caller's Origin. Because EventSource does not preflight and does not send cookies, the wildcard is sufficient to let any third-party page the developer visits open a cross-origin EventSource to the SSE port and read the live filename stream from JavaScript. This vulnerability is fixed in 1.17.7."}],"source":{"advisory":"GHSA-hw27-4v2q-5qff","discovery":"UNKNOWN"}},"adp":[{"references":[{"url":"https://github.com/xyproto/algernon/security/advisories/GHSA-hw27-4v2q-5qff","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-05-26T17:38:47.158630Z","id":"CVE-2026-46431","options":[{"Exploitation":"poc"},{"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":"2026-05-26T17:39:14.529Z"}}]}}