{"id":"CVE-2026-77581","aliases":["EUVD-2026-86229","GHSA-5xjf-rr5x-pcfj"],"status":"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.","severity":{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.00266,"percentile":0.18939,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-918"],"published":"2026-09-24T15:23:18Z","modified":"2026-10-28T02:30:43Z","products":[{"vendor":"alam00000","product":"bentopdf"}],"references":[{"url":"https://github.com/alam00000/bentopdf/security/advisories/GHSA-5xjf-rr5x-pcfj","tags":["x_refsource_CONFIRM","exploit","advisory"]},{"url":"https://github.com/alam00000/bentopdf/commit/45496fcd2ed6e02dcdde0d3839cc5024c091760c","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/alam00000/bentopdf/commit/58cd1a8893bfe06e4a59a72adc2e7db00a8b9266","tags":["x_refsource_MISC","fix"]},{"url":"https://github.com/alam00000/bentopdf/releases/tag/v2.8.7","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/77xxx/CVE-2026-77581.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-77581","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-77581","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.","status":"published","published":"2026-09-24T15:23:18.55Z","modified":"2026-09-24T15:37:29.237Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","level":"high","assessor":"cna"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:20:16.072351Z"}],"euvd":[{"id":"EUVD-2026-86229","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.","status":"published","published":"2026-09-24T15:23:18Z","modified":"2026-09-24T15:37:29Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","level":"high"}],"updated_at":"2026-11-02T17:27:56.686358Z"}],"nvd":[{"id":"CVE-2026-77581","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.","status":"published","published":"2026-09-24T16:17:10.943Z","modified":"2026-09-29T19:07:47.037Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","level":"high","assessor":"secondary"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T14:12:51.036099Z"}],"osv":[{"id":"CVE-2026-77581","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.","status":"published","published":"2026-09-24T15:23:18.55Z","modified":"2026-10-28T02:30:43.36072559Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:L","level":"high"}],"cwes":["CWE-918"],"updated_at":"2026-11-02T15:45:17.44708Z"}]}}