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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-199-27-135-147.cloudflare.comIn scope2026-11-14
cf-199-27-135-148.cloudflare.comIn scope2026-11-14
cf-199-27-135-149.cloudflare.comIn scope2026-11-14
cf-199-27-135-15.cloudflare.comIn scope2026-11-14
cf-199-27-135-150.cloudflare.comIn scope2026-11-14
cf-199-27-135-151.cloudflare.comIn scope2026-11-14
cf-199-27-135-152.cloudflare.comIn scope2026-11-14
cf-199-27-135-153.cloudflare.comIn scope2026-11-14
cf-199-27-135-154.cloudflare.comIn scope2026-11-14
cf-199-27-135-155.cloudflare.comIn scope2026-11-14
cf-199-27-135-156.cloudflare.comIn scope2026-11-14
cf-199-27-135-157.cloudflare.comIn scope2026-11-14
cf-199-27-135-158.cloudflare.comIn scope2026-11-14
cf-199-27-135-159.cloudflare.comIn scope2026-11-14
cf-199-27-135-16.cloudflare.comIn scope2026-11-14
cf-199-27-135-160.cloudflare.comIn scope2026-11-14
cf-199-27-135-161.cloudflare.comIn scope2026-11-14
cf-199-27-135-162.cloudflare.comIn scope2026-11-14
cf-199-27-135-163.cloudflare.comIn scope2026-11-14
cf-199-27-135-164.cloudflare.comIn scope2026-11-14
cf-199-27-135-165.cloudflare.comIn scope2026-11-14
cf-199-27-135-166.cloudflare.comIn scope2026-11-14
cf-199-27-135-167.cloudflare.comIn scope2026-11-14
cf-199-27-135-168.cloudflare.comIn scope2026-11-14
cf-199-27-135-169.cloudflare.comIn scope2026-11-14
cf-199-27-135-17.cloudflare.comIn scope2026-11-14
cf-199-27-135-170.cloudflare.comIn scope2026-11-14
cf-199-27-135-171.cloudflare.comIn scope2026-11-14
cf-199-27-135-172.cloudflare.comIn scope2026-11-14
cf-199-27-135-173.cloudflare.comIn scope2026-11-14
cf-199-27-135-174.cloudflare.comIn scope2026-11-14
cf-199-27-135-175.cloudflare.comIn scope2026-11-14
cf-199-27-135-176.cloudflare.comIn scope2026-11-14
cf-199-27-135-177.cloudflare.comIn scope2026-11-14
cf-199-27-135-178.cloudflare.comIn scope2026-11-14
cf-199-27-135-179.cloudflare.comIn scope2026-11-14
cf-199-27-135-18.cloudflare.comIn scope2026-11-14
cf-199-27-135-180.cloudflare.comIn scope2026-11-14
cf-199-27-135-181.cloudflare.comIn scope2026-11-14
cf-199-27-135-182.cloudflare.comIn scope2026-11-14
cf-199-27-135-183.cloudflare.comIn scope2026-11-14
cf-199-27-135-184.cloudflare.comIn scope2026-11-14
cf-199-27-135-185.cloudflare.comIn scope2026-11-14
cf-199-27-135-186.cloudflare.comIn scope2026-11-14
cf-199-27-135-187.cloudflare.comIn scope2026-11-14
cf-199-27-135-188.cloudflare.comIn scope2026-11-14
cf-199-27-135-189.cloudflare.comIn scope2026-11-14
cf-199-27-135-19.cloudflare.comIn scope2026-11-14
cf-199-27-135-190.cloudflare.comIn scope2026-11-14
cf-199-27-135-191.cloudflare.comIn scope2026-11-14
cf-199-27-135-192.cloudflare.comIn scope2026-11-14
cf-199-27-135-193.cloudflare.comIn scope2026-11-14
cf-199-27-135-194.cloudflare.comIn scope2026-11-14
cf-199-27-135-195.cloudflare.comIn scope2026-11-14
cf-199-27-135-196.cloudflare.comIn scope2026-11-14
cf-199-27-135-197.cloudflare.comIn scope2026-11-14
cf-199-27-135-198.cloudflare.comIn scope2026-11-14
cf-199-27-135-199.cloudflare.comIn scope2026-11-14
cf-199-27-135-20.cloudflare.comIn scope2026-11-14
cf-199-27-135-200.cloudflare.comIn scope2026-11-14
cf-199-27-135-201.cloudflare.comIn scope2026-11-14
cf-199-27-135-202.cloudflare.comIn scope2026-11-14
cf-199-27-135-203.cloudflare.comIn scope2026-11-14
cf-199-27-135-204.cloudflare.comIn scope2026-11-14
cf-199-27-135-205.cloudflare.comIn scope2026-11-14
cf-199-27-135-206.cloudflare.comIn scope2026-11-14
cf-199-27-135-207.cloudflare.comIn scope2026-11-14
cf-199-27-135-208.cloudflare.comIn scope2026-11-14
cf-199-27-135-209.cloudflare.comIn scope2026-11-14
cf-199-27-135-21.cloudflare.comIn scope2026-11-14
cf-199-27-135-210.cloudflare.comIn scope2026-11-14
cf-199-27-135-211.cloudflare.comIn scope2026-11-14
cf-199-27-135-212.cloudflare.comIn scope2026-11-14
cf-199-27-135-213.cloudflare.comIn scope2026-11-14
cf-199-27-135-214.cloudflare.comIn scope2026-11-14
cf-199-27-135-215.cloudflare.comIn scope2026-11-14
cf-199-27-135-216.cloudflare.comIn scope2026-11-14
cf-199-27-135-217.cloudflare.comIn scope2026-11-14
cf-199-27-135-218.cloudflare.comIn scope2026-11-14
cf-199-27-135-219.cloudflare.comIn scope2026-11-14
cf-199-27-135-22.cloudflare.comIn scope2026-11-14
cf-199-27-135-220.cloudflare.comIn scope2026-11-14
cf-199-27-135-221.cloudflare.comIn scope2026-11-14
cf-199-27-135-222.cloudflare.comIn scope2026-11-14
cf-199-27-135-223.cloudflare.comIn scope2026-11-14
cf-199-27-135-224.cloudflare.comIn scope2026-11-14
cf-199-27-135-225.cloudflare.comIn scope2026-11-14
cf-199-27-135-226.cloudflare.comIn scope2026-11-14
cf-199-27-135-227.cloudflare.comIn scope2026-11-14
cf-199-27-135-228.cloudflare.comIn scope2026-11-14
cf-199-27-135-229.cloudflare.comIn scope2026-11-14
cf-199-27-135-23.cloudflare.comIn scope2026-11-14
cf-199-27-135-230.cloudflare.comIn scope2026-11-14
cf-199-27-135-231.cloudflare.comIn scope2026-11-14
cf-199-27-135-232.cloudflare.comIn scope2026-11-14
cf-199-27-135-233.cloudflare.comIn scope2026-11-14
cf-199-27-135-234.cloudflare.comIn scope2026-11-14
cf-199-27-135-235.cloudflare.comIn scope2026-11-14
cf-199-27-135-236.cloudflare.comIn scope2026-11-14
cf-199-27-135-237.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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