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Bug bounty program

CP

Cloudflare Public Bug Bounty

Open on HackerOneAtlas
Platform
HackerOne
Bounties
Pays
Assets in scope
51
Disclosed reports
44
Subdomains
24,298
Vendor on CyberSIXT
Cloudflare (70 CVEs, 0 exploited)

Most upvoted reports44

All reports
Most upvoted reports of Cloudflare Public Bug Bounty
ReportWeaknessDisclosedBountyVotes
HTTP Request Smuggling in Transform Rules using hexadecimal escape sequences in the concat() functionAnalysed#1478633Injection and Smuggling2022-05-16$6,000116
Cloudflare CASB Confused Deputy ProblemAnalysed#1952124No weakness recorded2023-06-07$3,30097
Using special IPv4-mapped IPv6 addresses to bypass local IP banAnalysed#1785260No weakness recorded2023-01-24$7,50078
Bypass of Cloudflare's Cache Keys and WAF via header overflow#3027461Access Control2025-11-18–77
Hijack all emails sent to any domain that uses Cloudflare Email ForwardingAnalysed#1419341Access Control2022-07-28$6,00076
`use-mcp`'s oauth2 process uses a window.open call with untrusted mcp server provided data allowing for code execution under the page using itAnalysed#3211031Cross-site Scripting2025-09-30$55075
Yet Another CASB Integration Takeover of Active IntegrationsAnalysed#2094346No weakness recorded2023-11-13–68
[Variation of #3321406] YetAnother 1-Click Chaining of Self-XSS, Cookie Tossing and AntiCSRF Token Prediction leads to auto approval in AccessTempAuthAnalysed#3423950Cross-site Scripting2026-04-14–63
AI Playground XSS to steal user-chat messages and access to connected MCP ServerAnalysed#3424998Cross-site Scripting2026-02-26–62
Bypass R2 payment screenAnalysed#2170559Authentication2023-11-10$35057

Subdomains24,298

Root
Scope
Name suggests
First seen
Text file24,298 names
Subdomains of Cloudflare Public Bug Bounty
NameScopeFirst seen
cf-199-27-135-238.cloudflare.comIn scope2026-11-14
cf-199-27-135-239.cloudflare.comIn scope2026-11-14
cf-199-27-135-24.cloudflare.comIn scope2026-11-14
cf-199-27-135-240.cloudflare.comIn scope2026-11-14
cf-199-27-135-241.cloudflare.comIn scope2026-11-14
cf-199-27-135-242.cloudflare.comIn scope2026-11-14
cf-199-27-135-243.cloudflare.comIn scope2026-11-14
cf-199-27-135-244.cloudflare.comIn scope2026-11-14
cf-199-27-135-245.cloudflare.comIn scope2026-11-14
cf-199-27-135-246.cloudflare.comIn scope2026-11-14
cf-199-27-135-247.cloudflare.comIn scope2026-11-14
cf-199-27-135-248.cloudflare.comIn scope2026-11-14
cf-199-27-135-249.cloudflare.comIn scope2026-11-14
cf-199-27-135-25.cloudflare.comIn scope2026-11-14
cf-199-27-135-250.cloudflare.comIn scope2026-11-14
cf-199-27-135-26.cloudflare.comIn scope2026-11-14
cf-199-27-135-27.cloudflare.comIn scope2026-11-14
cf-199-27-135-28.cloudflare.comIn scope2026-11-14
cf-199-27-135-29.cloudflare.comIn scope2026-11-14
cf-199-27-135-30.cloudflare.comIn scope2026-11-14
cf-199-27-135-31.cloudflare.comIn scope2026-11-14
cf-199-27-135-32.cloudflare.comIn scope2026-11-14
cf-199-27-135-33.cloudflare.comIn scope2026-11-14
cf-199-27-135-34.cloudflare.comIn scope2026-11-14
cf-199-27-135-35.cloudflare.comIn scope2026-11-14
cf-199-27-135-36.cloudflare.comIn scope2026-11-14
cf-199-27-135-37.cloudflare.comIn scope2026-11-14
cf-199-27-135-38.cloudflare.comIn scope2026-11-14
cf-199-27-135-39.cloudflare.comIn scope2026-11-14
cf-199-27-135-40.cloudflare.comIn scope2026-11-14
cf-199-27-135-41.cloudflare.comIn scope2026-11-14
cf-199-27-135-42.cloudflare.comIn scope2026-11-14
cf-199-27-135-43.cloudflare.comIn scope2026-11-14
cf-199-27-135-44.cloudflare.comIn scope2026-11-14
cf-199-27-135-45.cloudflare.comIn scope2026-11-14
cf-199-27-135-46.cloudflare.comIn scope2026-11-14
cf-199-27-135-47.cloudflare.comIn scope2026-11-14
cf-199-27-135-48.cloudflare.comIn scope2026-11-14
cf-199-27-135-49.cloudflare.comIn scope2026-11-14
cf-199-27-135-5.cloudflare.comIn scope2026-11-14
cf-199-27-135-50.cloudflare.comIn scope2026-11-14
cf-199-27-135-51.cloudflare.comIn scope2026-11-14
cf-199-27-135-52.cloudflare.comIn scope2026-11-14
cf-199-27-135-5245-50-148.cloudflare.comIn scope2026-11-14
cf-199-27-135-53.cloudflare.comIn scope2026-11-14
cf-199-27-135-54.cloudflare.comIn scope2026-11-14
cf-199-27-135-55.cloudflare.comIn scope2026-11-14
cf-199-27-135-56.cloudflare.comIn scope2026-11-14
cf-199-27-135-57.cloudflare.comIn scope2026-11-14
cf-199-27-135-58.cloudflare.comIn scope2026-11-14
cf-199-27-135-59.cloudflare.comIn scope2026-11-14
cf-199-27-135-6.cloudflare.comIn scope2026-11-14
cf-199-27-135-60.cloudflare.comIn scope2026-11-14
cf-199-27-135-61.cloudflare.comIn scope2026-11-14
cf-199-27-135-62.cloudflare.comIn scope2026-11-14
cf-199-27-135-63.cloudflare.comIn scope2026-11-14
cf-199-27-135-64.cloudflare.comIn scope2026-11-14
cf-199-27-135-65.cloudflare.comIn scope2026-11-14
cf-199-27-135-66.cloudflare.comIn scope2026-11-14
cf-199-27-135-67.cloudflare.comIn scope2026-11-14
cf-199-27-135-68.cloudflare.comIn scope2026-11-14
cf-199-27-135-69.cloudflare.comIn scope2026-11-14
cf-199-27-135-7.cloudflare.comIn scope2026-11-14
cf-199-27-135-70.cloudflare.comIn scope2026-11-14
cf-199-27-135-71.cloudflare.comIn scope2026-11-14
cf-199-27-135-72.cloudflare.comIn scope2026-11-14
cf-199-27-135-73.cloudflare.comIn scope2026-11-14
cf-199-27-135-74.cloudflare.comIn scope2026-11-14
cf-199-27-135-75.cloudflare.comIn scope2026-11-14
cf-199-27-135-76.cloudflare.comIn scope2026-11-14
cf-199-27-135-77.cloudflare.comIn scope2026-11-14
cf-199-27-135-78.cloudflare.comIn scope2026-11-14
cf-199-27-135-79.cloudflare.comIn scope2026-11-14
cf-199-27-135-8.cloudflare.comIn scope2026-11-14
cf-199-27-135-80.cloudflare.comIn scope2026-11-14
cf-199-27-135-81.cloudflare.comIn scope2026-11-14
cf-199-27-135-82.cloudflare.comIn scope2026-11-14
cf-199-27-135-83.cloudflare.comIn scope2026-11-14
cf-199-27-135-84.cloudflare.comIn scope2026-11-14
cf-199-27-135-85.cloudflare.comIn scope2026-11-14
cf-199-27-135-86.cloudflare.comIn scope2026-11-14
cf-199-27-135-87.cloudflare.comIn scope2026-11-14
cf-199-27-135-88.cloudflare.comIn scope2026-11-14
cf-199-27-135-89.cloudflare.comIn scope2026-11-14
cf-199-27-135-9.cloudflare.comIn scope2026-11-14
cf-199-27-135-90.cloudflare.comIn scope2026-11-14
cf-199-27-135-91.cloudflare.comIn scope2026-11-14
cf-199-27-135-92.cloudflare.comIn scope2026-11-14
cf-199-27-135-93.cloudflare.comIn scope2026-11-14
cf-199-27-135-94.cloudflare.comIn scope2026-11-14
cf-199-27-135-96.cloudflare.comIn scope2026-11-14
cf-199-27-135-97.cloudflare.comIn scope2026-11-14
cf-199-27-135-98.cloudflare.comIn scope2026-11-14
cf-199-27-135-99.cloudflare.comIn scope2026-11-14
cf-204-93-173-2.cloudflare.comIn scope2026-11-14
cf-204-93-173-3.cloudflare.comIn scope2026-11-14
cf-204-93-173-4.cloudflare.comIn scope2026-11-14
cf-204-93-173-5.cloudflare.comIn scope2026-11-14
cf-204-93-173-6.cloudflare.comIn scope2026-11-14
cf-204-93-173-7.cloudflare.comIn scope2026-11-14

18,935 names are covered by the program's own scope; 2 were first seen this week. Names come from ProjectDiscovery's public Chaos dataset (passive sources: certificate logs, DNS and other public data), matched to the program by its listing and its own domain scope. A name being in a dataset is not permission to test it: only what the program's own scope says is in scope, and its policy decides. CyberSIXT does not resolve, probe or scan these names. Tags come from the name alone. Source: ProjectDiscovery Chaos. Subdomains on the Atlas, or search the subdomains of every program.

A name in a dataset is not permission to test it: the program's own scope and rules decide. Data as of 2026-11-15.

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Updated