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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-199-27-134-186.cloudflare.comIn scope2026-11-14
cf-199-27-134-187.cloudflare.comIn scope2026-11-14
cf-199-27-134-188.cloudflare.comIn scope2026-11-14
cf-199-27-134-189.cloudflare.comIn scope2026-11-14
cf-199-27-134-19.cloudflare.comIn scope2026-11-14
cf-199-27-134-190.cloudflare.comIn scope2026-11-14
cf-199-27-134-191.cloudflare.comIn scope2026-11-14
cf-199-27-134-192.cloudflare.comIn scope2026-11-14
cf-199-27-134-193.cloudflare.comIn scope2026-11-14
cf-199-27-134-194.cloudflare.comIn scope2026-11-14
cf-199-27-134-195.cloudflare.comIn scope2026-11-14
cf-199-27-134-196.cloudflare.comIn scope2026-11-14
cf-199-27-134-197.cloudflare.comIn scope2026-11-14
cf-199-27-134-198.cloudflare.comIn scope2026-11-14
cf-199-27-134-199.cloudflare.comIn scope2026-11-14
cf-199-27-134-20.cloudflare.comIn scope2026-11-14
cf-199-27-134-200.cloudflare.comIn scope2026-11-14
cf-199-27-134-201.cloudflare.comIn scope2026-11-14
cf-199-27-134-202.cloudflare.comIn scope2026-11-14
cf-199-27-134-203.cloudflare.comIn scope2026-11-14
cf-199-27-134-204.cloudflare.comIn scope2026-11-14
cf-199-27-134-205.cloudflare.comIn scope2026-11-14
cf-199-27-134-206.cloudflare.comIn scope2026-11-14
cf-199-27-134-207.cloudflare.comIn scope2026-11-14
cf-199-27-134-208.cloudflare.comIn scope2026-11-14
cf-199-27-134-209.cloudflare.comIn scope2026-11-14
cf-199-27-134-21.cloudflare.comIn scope2026-11-14
cf-199-27-134-210.cloudflare.comIn scope2026-11-14
cf-199-27-134-211.cloudflare.comIn scope2026-11-14
cf-199-27-134-212.cloudflare.comIn scope2026-11-14
cf-199-27-134-213.cloudflare.comIn scope2026-11-14
cf-199-27-134-214.cloudflare.comIn scope2026-11-14
cf-199-27-134-215.cloudflare.comIn scope2026-11-14
cf-199-27-134-216.cloudflare.comIn scope2026-11-14
cf-199-27-134-217.cloudflare.comIn scope2026-11-14
cf-199-27-134-218.cloudflare.comIn scope2026-11-14
cf-199-27-134-219.cloudflare.comIn scope2026-11-14
cf-199-27-134-22.cloudflare.comIn scope2026-11-14
cf-199-27-134-220.cloudflare.comIn scope2026-11-14
cf-199-27-134-221.cloudflare.comIn scope2026-11-14
cf-199-27-134-222.cloudflare.comIn scope2026-11-14
cf-199-27-134-223.cloudflare.comIn scope2026-11-14
cf-199-27-134-224.cloudflare.comIn scope2026-11-14
cf-199-27-134-225.cloudflare.comIn scope2026-11-14
cf-199-27-134-226.cloudflare.comIn scope2026-11-14
cf-199-27-134-227.cloudflare.comIn scope2026-11-14
cf-199-27-134-228.cloudflare.comIn scope2026-11-14
cf-199-27-134-229.cloudflare.comIn scope2026-11-14
cf-199-27-134-23.cloudflare.comIn scope2026-11-14
cf-199-27-134-230.cloudflare.comIn scope2026-11-14
cf-199-27-134-231.cloudflare.comIn scope2026-11-14
cf-199-27-134-232.cloudflare.comIn scope2026-11-14
cf-199-27-134-233.cloudflare.comIn scope2026-11-14
cf-199-27-134-234.cloudflare.comIn scope2026-11-14
cf-199-27-134-235.cloudflare.comIn scope2026-11-14
cf-199-27-134-236.cloudflare.comIn scope2026-11-14
cf-199-27-134-237.cloudflare.comIn scope2026-11-14
cf-199-27-134-238.cloudflare.comIn scope2026-11-14
cf-199-27-134-239.cloudflare.comIn scope2026-11-14
cf-199-27-134-24.cloudflare.comIn scope2026-11-14
cf-199-27-134-240.cloudflare.comIn scope2026-11-14
cf-199-27-134-241.cloudflare.comIn scope2026-11-14
cf-199-27-134-242.cloudflare.comIn scope2026-11-14
cf-199-27-134-243.cloudflare.comIn scope2026-11-14
cf-199-27-134-244.cloudflare.comIn scope2026-11-14
cf-199-27-134-245.cloudflare.comIn scope2026-11-14
cf-199-27-134-246.cloudflare.comIn scope2026-11-14
cf-199-27-134-247.cloudflare.comIn scope2026-11-14
cf-199-27-134-248.cloudflare.comIn scope2026-11-14
cf-199-27-134-249.cloudflare.comIn scope2026-11-14
cf-199-27-134-25.cloudflare.comIn scope2026-11-14
cf-199-27-134-250.cloudflare.comIn scope2026-11-14
cf-199-27-134-26.cloudflare.comIn scope2026-11-14
cf-199-27-134-27.cloudflare.comIn scope2026-11-14
cf-199-27-134-28.cloudflare.comIn scope2026-11-14
cf-199-27-134-29.cloudflare.comIn scope2026-11-14
cf-199-27-134-30.cloudflare.comIn scope2026-11-14
cf-199-27-134-31.cloudflare.comIn scope2026-11-14
cf-199-27-134-32.cloudflare.comIn scope2026-11-14
cf-199-27-134-33.cloudflare.comIn scope2026-11-14
cf-199-27-134-34.cloudflare.comIn scope2026-11-14
cf-199-27-134-35.cloudflare.comIn scope2026-11-14
cf-199-27-134-36.cloudflare.comIn scope2026-11-14
cf-199-27-134-37.cloudflare.comIn scope2026-11-14
cf-199-27-134-38.cloudflare.comIn scope2026-11-14
cf-199-27-134-39.cloudflare.comIn scope2026-11-14
cf-199-27-134-40.cloudflare.comIn scope2026-11-14
cf-199-27-134-41.cloudflare.comIn scope2026-11-14
cf-199-27-134-42.cloudflare.comIn scope2026-11-14
cf-199-27-134-43.cloudflare.comIn scope2026-11-14
cf-199-27-134-44.cloudflare.comIn scope2026-11-14
cf-199-27-134-45.cloudflare.comIn scope2026-11-14
cf-199-27-134-46.cloudflare.comIn scope2026-11-14
cf-199-27-134-47.cloudflare.comIn scope2026-11-14
cf-199-27-134-48.cloudflare.comIn scope2026-11-14
cf-199-27-134-49.cloudflare.comIn scope2026-11-14
cf-199-27-134-5.cloudflare.comIn scope2026-11-14
cf-199-27-134-50.cloudflare.comIn scope2026-11-14
cf-199-27-134-51.cloudflare.comIn scope2026-11-14
cf-199-27-134-52.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