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Bug bounty program

CP

Cloudflare Public Bug Bounty

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

Subdomains of Cloudflare Public Bug Bounty
NameScopeFirst seen
cf-190-93-240-208.cloudflare.comIn scope2026-11-14
cf-190-93-240-209.cloudflare.comIn scope2026-11-14
cf-190-93-240-21.cloudflare.comIn scope2026-11-14
cf-190-93-240-210.cloudflare.comIn scope2026-11-14
cf-190-93-240-211.cloudflare.comIn scope2026-11-14
cf-190-93-240-212.cloudflare.comIn scope2026-11-14
cf-190-93-240-213.cloudflare.comIn scope2026-11-14
cf-190-93-240-214.cloudflare.comIn scope2026-11-14
cf-190-93-240-215.cloudflare.comIn scope2026-11-14
cf-190-93-240-216.cloudflare.comIn scope2026-11-14
cf-190-93-240-217.cloudflare.comIn scope2026-11-14
cf-190-93-240-218.cloudflare.comIn scope2026-11-14
cf-190-93-240-219.cloudflare.comIn scope2026-11-14
cf-190-93-240-22.cloudflare.comIn scope2026-11-14
cf-190-93-240-220.cloudflare.comIn scope2026-11-14
cf-190-93-240-221.cloudflare.comIn scope2026-11-14
cf-190-93-240-222.cloudflare.comIn scope2026-11-14
cf-190-93-240-223.cloudflare.comIn scope2026-11-14
cf-190-93-240-224.cloudflare.comIn scope2026-11-14
cf-190-93-240-225.cloudflare.comIn scope2026-11-14
cf-190-93-240-226.cloudflare.comIn scope2026-11-14
cf-190-93-240-227.cloudflare.comIn scope2026-11-14
cf-190-93-240-228.cloudflare.comIn scope2026-11-14
cf-190-93-240-229.cloudflare.comIn scope2026-11-14
cf-190-93-240-23.cloudflare.comIn scope2026-11-14
cf-190-93-240-230.cloudflare.comIn scope2026-11-14
cf-190-93-240-231.cloudflare.comIn scope2026-11-14
cf-190-93-240-232.cloudflare.comIn scope2026-11-14
cf-190-93-240-233.cloudflare.comIn scope2026-11-14
cf-190-93-240-234.cloudflare.comIn scope2026-11-14
cf-190-93-240-235.cloudflare.comIn scope2026-11-14
cf-190-93-240-236.cloudflare.comIn scope2026-11-14
cf-190-93-240-237.cloudflare.comIn scope2026-11-14
cf-190-93-240-238.cloudflare.comIn scope2026-11-14
cf-190-93-240-239.cloudflare.comIn scope2026-11-14
cf-190-93-240-24.cloudflare.comIn scope2026-11-14
cf-190-93-240-240.cloudflare.comIn scope2026-11-14
cf-190-93-240-241.cloudflare.comIn scope2026-11-14
cf-190-93-240-242.cloudflare.comIn scope2026-11-14
cf-190-93-240-243.cloudflare.comIn scope2026-11-14
cf-190-93-240-244.cloudflare.comIn scope2026-11-14
cf-190-93-240-245.cloudflare.comIn scope2026-11-14
cf-190-93-240-246.cloudflare.comIn scope2026-11-14
cf-190-93-240-247.cloudflare.comIn scope2026-11-14
cf-190-93-240-248.cloudflare.comIn scope2026-11-14
cf-190-93-240-249.cloudflare.comIn scope2026-11-14
cf-190-93-240-25.cloudflare.comIn scope2026-11-14
cf-190-93-240-250.cloudflare.comIn scope2026-11-14
cf-190-93-240-251.cloudflare.comIn scope2026-11-14
cf-190-93-240-252.cloudflare.comIn scope2026-11-14
cf-190-93-240-253.cloudflare.comIn scope2026-11-14
cf-190-93-240-254.cloudflare.comIn scope2026-11-14
cf-190-93-240-26.cloudflare.comIn scope2026-11-14
cf-190-93-240-27.cloudflare.comIn scope2026-11-14
cf-190-93-240-28.cloudflare.comIn scope2026-11-14
cf-190-93-240-29.cloudflare.comIn scope2026-11-14
cf-190-93-240-30.cloudflare.comIn scope2026-11-14
cf-190-93-240-31.cloudflare.comIn scope2026-11-14
cf-190-93-240-32.cloudflare.comIn scope2026-11-14
cf-190-93-240-33.cloudflare.comIn scope2026-11-14
cf-190-93-240-34.cloudflare.comIn scope2026-11-14
cf-190-93-240-35.cloudflare.comIn scope2026-11-14
cf-190-93-240-36.cloudflare.comIn scope2026-11-14
cf-190-93-240-37.cloudflare.comIn scope2026-11-14
cf-190-93-240-38.cloudflare.comIn scope2026-11-14
cf-190-93-240-39.cloudflare.comIn scope2026-11-14
cf-190-93-240-4.cloudflare.comIn scope2026-11-14
cf-190-93-240-40.cloudflare.comIn scope2026-11-14
cf-190-93-240-41.cloudflare.comIn scope2026-11-14
cf-190-93-240-42.cloudflare.comIn scope2026-11-14
cf-190-93-240-43.cloudflare.comIn scope2026-11-14
cf-190-93-240-44.cloudflare.comIn scope2026-11-14
cf-190-93-240-45.cloudflare.comIn scope2026-11-14
cf-190-93-240-46.cloudflare.comIn scope2026-11-14
cf-190-93-240-47.cloudflare.comIn scope2026-11-14
cf-190-93-240-48.cloudflare.comIn scope2026-11-14
cf-190-93-240-49.cloudflare.comIn scope2026-11-14
cf-190-93-240-5.cloudflare.comIn scope2026-11-14
cf-190-93-240-50.cloudflare.comIn scope2026-11-14
cf-190-93-240-51.cloudflare.comIn scope2026-11-14
cf-190-93-240-52.cloudflare.comIn scope2026-11-14
cf-190-93-240-53.cloudflare.comIn scope2026-11-14
cf-190-93-240-54.cloudflare.comIn scope2026-11-14
cf-190-93-240-55.cloudflare.comIn scope2026-11-14
cf-190-93-240-56.cloudflare.comIn scope2026-11-14
cf-190-93-240-57.cloudflare.comIn scope2026-11-14
cf-190-93-240-58.cloudflare.comIn scope2026-11-14
cf-190-93-240-59.cloudflare.comIn scope2026-11-14
cf-190-93-240-6.cloudflare.comIn scope2026-11-14
cf-190-93-240-60.cloudflare.comIn scope2026-11-14
cf-190-93-240-61.cloudflare.comIn scope2026-11-14
cf-190-93-240-62.cloudflare.comIn scope2026-11-14
cf-190-93-240-63.cloudflare.comIn scope2026-11-14
cf-190-93-240-64.cloudflare.comIn scope2026-11-14
cf-190-93-240-65.cloudflare.comIn scope2026-11-14
cf-190-93-240-66.cloudflare.comIn scope2026-11-14
cf-190-93-240-67.cloudflare.comIn scope2026-11-14
cf-190-93-240-68.cloudflare.comIn scope2026-11-14
cf-190-93-240-69.cloudflare.comIn scope2026-11-14
cf-190-93-240-7.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.