{"api_version":"1","generated_at":"2026-05-08T11:00:24+00:00","cve":"CVE-2026-42261","urls":{"html":"https://cve.report/CVE-2026-42261","api":"https://cve.report/api/cve/CVE-2026-42261.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-42261","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-42261"},"summary":{"title":"PromptHub: Authenticated SSRF via IPv6 filter bypass in `POST /api/skills/fetch-remote`","description":"PromptHub is an all-in-one AI toolbox for prompt, skill, and agent management. From version 0.4.9 to before version 0.5.4, apps/web/src/routes/skills.ts exposes an authenticated endpoint POST /api/skills/fetch-remote that fetches a user-supplied URL server-side and reflects the response body (up to 5 MB) back to the caller. The SSRF protection in apps/web/src/utils/remote-http.ts (isPrivateIPv6) attempts to block private/loopback destinations, but multiple alternate-but-valid IPv6 representations bypass the check. The bypasses reach any IPv4 address (loopback, RFC1918, link-local) via IPv4-mapped IPv6 in hex form, and the canonical ::1 via any representation that isn't the literal string \"::1\". Any authenticated user (role: user or admin) can trigger the SSRF. On deployments configured with ALLOW_REGISTRATION=true — a supported and documented configuration — this means any internet user who can register. This issue has been patched in version 0.5.4.","state":"PUBLISHED","assigner":"GitHub_M","published_at":"2026-05-08 04:16:20","updated_at":"2026-05-08 04:16:20"},"problem_types":["CWE-20","CWE-693","CWE-918","CWE-20 CWE-20: Improper Input Validation","CWE-693 CWE-693: Protection Mechanism Failure","CWE-918 CWE-918: Server-Side Request Forgery (SSRF)"],"metrics":[{"version":"3.1","source":"security-advisories@github.com","type":"Secondary","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"LOW","availabilityImpact":"NONE"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","data":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","version":"3.1"}}],"references":[{"url":"https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6","name":"https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://github.com/legeling/PromptHub/releases/tag/v0.5.4","name":"https://github.com/legeling/PromptHub/releases/tag/v0.5.4","refsource":"security-advisories@github.com","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-42261","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42261","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"legeling","product":"PromptHub","version":"affected >= 0.4.9, < 0.5.4","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"product":"PromptHub","vendor":"legeling","versions":[{"status":"affected","version":">= 0.4.9, < 0.5.4"}]}],"descriptions":[{"lang":"en","value":"PromptHub is an all-in-one AI toolbox for prompt, skill, and agent management. 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This issue has been patched in version 0.5.4."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":7.1,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-20","description":"CWE-20: Improper Input Validation","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-693","description":"CWE-693: Protection Mechanism Failure","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-918","description":"CWE-918: Server-Side Request Forgery (SSRF)","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-05-08T03:11:25.305Z","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","shortName":"GitHub_M"},"references":[{"name":"https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6","tags":["x_refsource_CONFIRM"],"url":"https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6"},{"name":"https://github.com/legeling/PromptHub/releases/tag/v0.5.4","tags":["x_refsource_MISC"],"url":"https://github.com/legeling/PromptHub/releases/tag/v0.5.4"}],"source":{"advisory":"GHSA-9fhh-fjfg-5mr6","discovery":"UNKNOWN"},"title":"PromptHub: Authenticated SSRF via IPv6 filter bypass in `POST /api/skills/fetch-remote`"}},"cveMetadata":{"assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","assignerShortName":"GitHub_M","cveId":"CVE-2026-42261","datePublished":"2026-05-08T03:11:25.305Z","dateReserved":"2026-04-26T11:53:27.705Z","dateUpdated":"2026-05-08T03:11:25.305Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-08 04:16:20","lastModifiedDate":"2026-05-08 04:16:20","problem_types":["CWE-20","CWE-693","CWE-918","CWE-20 CWE-20: Improper Input Validation","CWE-693 CWE-693: Protection Mechanism Failure","CWE-918 CWE-918: Server-Side Request Forgery (SSRF)"],"metrics":{"cvssMetricV31":[{"source":"security-advisories@github.com","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"LOW","availabilityImpact":"NONE"},"exploitabilityScore":2.8,"impactScore":4.2}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"42261","Ordinal":"1","Title":"PromptHub: Authenticated SSRF via IPv6 filter bypass in `POST /a","CVE":"CVE-2026-42261","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"42261","Ordinal":"1","NoteData":"PromptHub is an all-in-one AI toolbox for prompt, skill, and agent management. From version 0.4.9 to before version 0.5.4, apps/web/src/routes/skills.ts exposes an authenticated endpoint POST /api/skills/fetch-remote that fetches a user-supplied URL server-side and reflects the response body (up to 5 MB) back to the caller. The SSRF protection in apps/web/src/utils/remote-http.ts (isPrivateIPv6) attempts to block private/loopback destinations, but multiple alternate-but-valid IPv6 representations bypass the check. The bypasses reach any IPv4 address (loopback, RFC1918, link-local) via IPv4-mapped IPv6 in hex form, and the canonical ::1 via any representation that isn't the literal string \"::1\". Any authenticated user (role: user or admin) can trigger the SSRF. On deployments configured with ALLOW_REGISTRATION=true — a supported and documented configuration — this means any internet user who can register. This issue has been patched in version 0.5.4.","Type":"Description","Title":"PromptHub: Authenticated SSRF via IPv6 filter bypass in `POST /a"}]}}}