{"id":"CVE-2026-77581","state":"PUBLISHED","title":"BentoPDF: SSRF in cors-proxy-worker.js via DNS-based hostname allowlist bypass","description":"BentoPDF is a client-side PDF toolkit that is self hostable. In 2.8.6 and earlier, the certificate and timestamp CORS proxy in cloudflare/cors-proxy-worker.js uses isPrivateOrReservedHost() to validate a supplied hostname separately from the DNS resolution used by fetch(targetUrl), allowing an attacker-controlled hostname to resolve to an internal or reserved destination after validation. A certificate-like path can satisfy ALLOWED_PATH_PATTERNS, and direct clients can forge the browser-oriented Origin header. Deployments without PROXY_SECRET skip the optional signature check, while the signature is an anti-abuse measure rather than a destination-security boundary. The proxy has a 10 MB response limit and can relay response bodies from reachable destinations. The advisory identifies both the official Worker deployment and self-hosted instances as impacted where the Worker execution environment can reach internal or reserved destinations. This vulnerability is fixed in 2.8.7.","publishedAt":"2026-09-24T15:23:18.550Z","updatedAt":"2026-09-24T15:37:29.237Z","severity":{"score":8.6,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["alam00000 bentopdf"],"affected":[{"vendor":"alam00000","product":"bentopdf","versions":[{"version":"< 2.8.7","status":"affected"}]}],"references":["https://github.com/alam00000/bentopdf/security/advisories/GHSA-5xjf-rr5x-pcfj","https://github.com/alam00000/bentopdf/commit/45496fcd2ed6e02dcdde0d3839cc5024c091760c","https://github.com/alam00000/bentopdf/commit/58cd1a8893bfe06e4a59a72adc2e7db00a8b9266","https://github.com/alam00000/bentopdf/releases/tag/v2.8.7"],"weaknesses":["CWE-918"],"ingestedAt":"2026-10-29T20:13:07.220Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/77xxx/CVE-2026-77581.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-77581","state":"PUBLISHED","datePublished":"2026-09-24T15:23:18.550Z","dateUpdated":"2026-09-24T15:37:29.237Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-20T20:35:30.148Z"},"containers":{"cna":{"title":"BentoPDF: SSRF in cors-proxy-worker.js via DNS-based hostname allowlist bypass","descriptions":[{"lang":"en","value":"BentoPDF is a client-side PDF toolkit that is self hostable. In 2.8.6 and earlier, the certificate and timestamp CORS proxy in cloudflare/cors-proxy-worker.js uses isPrivateOrReservedHost() to validate a supplied hostname separately from the DNS resolution used by fetch(targetUrl), allowing an attacker-controlled hostname to resolve to an internal or reserved destination after validation. A certificate-like path can satisfy ALLOWED_PATH_PATTERNS, and direct clients can forge the browser-oriented Origin header. Deployments without PROXY_SECRET skip the optional signature check, while the signature is an anti-abuse measure rather than a destination-security boundary. The proxy has a 10 MB response limit and can relay response bodies from reachable destinations. The advisory identifies both the official Worker deployment and self-hosted instances as impacted where the Worker execution environment can reach internal or reserved destinations. This vulnerability is fixed in 2.8.7."}],"affected":[{"vendor":"alam00000","product":"bentopdf","versions":[{"version":"< 2.8.7","status":"affected"}]}],"references":[{"url":"https://github.com/alam00000/bentopdf/security/advisories/GHSA-5xjf-rr5x-pcfj","name":"https://github.com/alam00000/bentopdf/security/advisories/GHSA-5xjf-rr5x-pcfj","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/alam00000/bentopdf/commit/45496fcd2ed6e02dcdde0d3839cc5024c091760c","name":"https://github.com/alam00000/bentopdf/commit/45496fcd2ed6e02dcdde0d3839cc5024c091760c","tags":["x_refsource_MISC"]},{"url":"https://github.com/alam00000/bentopdf/commit/58cd1a8893bfe06e4a59a72adc2e7db00a8b9266","name":"https://github.com/alam00000/bentopdf/commit/58cd1a8893bfe06e4a59a72adc2e7db00a8b9266","tags":["x_refsource_MISC"]},{"url":"https://github.com/alam00000/bentopdf/releases/tag/v2.8.7","name":"https://github.com/alam00000/bentopdf/releases/tag/v2.8.7","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"LOW","baseScore":8.6,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","version":"3.1"}}],"problemTypes":[{"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":"2026-09-24T15:23:18.550Z"},"source":{"advisory":"GHSA-5xjf-rr5x-pcfj","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","references":[{"url":"https://github.com/alam00000/bentopdf/security/advisories/GHSA-5xjf-rr5x-pcfj","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-24T15:37:09.697885Z","id":"CVE-2026-77581","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-09-24T15:37:29.237Z"}}]}}}