{"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"}}]}}

{}

{"cveTags": [], "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."}], "id": "CVE-2026-46431", "lastModified": "2026-05-26T17:16:51.100", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 2.8, "impactScore": 1.4, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-05-26T17:16:51.100", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/xyproto/algernon/security/advisories/GHSA-hw27-4v2q-5qff"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-942"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{}