Skip to content

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-198-41-223-149.cloudflare.comIn scope2026-11-14
cf-198-41-223-15.cloudflare.comIn scope2026-11-14
cf-198-41-223-150.cloudflare.comIn scope2026-11-14
cf-198-41-223-151.cloudflare.comIn scope2026-11-14
cf-198-41-223-152.cloudflare.comIn scope2026-11-14
cf-198-41-223-153.cloudflare.comIn scope2026-11-14
cf-198-41-223-154.cloudflare.comIn scope2026-11-14
cf-198-41-223-155.cloudflare.comIn scope2026-11-14
cf-198-41-223-156.cloudflare.comIn scope2026-11-14
cf-198-41-223-157.cloudflare.comIn scope2026-11-14
cf-198-41-223-158.cloudflare.comIn scope2026-11-14
cf-198-41-223-159.cloudflare.comIn scope2026-11-14
cf-198-41-223-16.cloudflare.comIn scope2026-11-14
cf-198-41-223-160.cloudflare.comIn scope2026-11-14
cf-198-41-223-161.cloudflare.comIn scope2026-11-14
cf-198-41-223-162.cloudflare.comIn scope2026-11-14
cf-198-41-223-163.cloudflare.comIn scope2026-11-14
cf-198-41-223-164.cloudflare.comIn scope2026-11-14
cf-198-41-223-165.cloudflare.comIn scope2026-11-14
cf-198-41-223-166.cloudflare.comIn scope2026-11-14
cf-198-41-223-167.cloudflare.comIn scope2026-11-14
cf-198-41-223-168.cloudflare.comIn scope2026-11-14
cf-198-41-223-169.cloudflare.comIn scope2026-11-14
cf-198-41-223-17.cloudflare.comIn scope2026-11-14
cf-198-41-223-170.cloudflare.comIn scope2026-11-14
cf-198-41-223-171.cloudflare.comIn scope2026-11-14
cf-198-41-223-172.cloudflare.comIn scope2026-11-14
cf-198-41-223-173.cloudflare.comIn scope2026-11-14
cf-198-41-223-174.cloudflare.comIn scope2026-11-14
cf-198-41-223-175.cloudflare.comIn scope2026-11-14
cf-198-41-223-176.cloudflare.comIn scope2026-11-14
cf-198-41-223-177.cloudflare.comIn scope2026-11-14
cf-198-41-223-178.cloudflare.comIn scope2026-11-14
cf-198-41-223-179.cloudflare.comIn scope2026-11-14
cf-198-41-223-18.cloudflare.comIn scope2026-11-14
cf-198-41-223-180.cloudflare.comIn scope2026-11-14
cf-198-41-223-181.cloudflare.comIn scope2026-11-14
cf-198-41-223-182.cloudflare.comIn scope2026-11-14
cf-198-41-223-183.cloudflare.comIn scope2026-11-14
cf-198-41-223-184.cloudflare.comIn scope2026-11-14
cf-198-41-223-185.cloudflare.comIn scope2026-11-14
cf-198-41-223-186.cloudflare.comIn scope2026-11-14
cf-198-41-223-187.cloudflare.comIn scope2026-11-14
cf-198-41-223-188.cloudflare.comIn scope2026-11-14
cf-198-41-223-189.cloudflare.comIn scope2026-11-14
cf-198-41-223-19.cloudflare.comIn scope2026-11-14
cf-198-41-223-190.cloudflare.comIn scope2026-11-14
cf-198-41-223-191.cloudflare.comIn scope2026-11-14
cf-198-41-223-192.cloudflare.comIn scope2026-11-14
cf-198-41-223-193.cloudflare.comIn scope2026-11-14
cf-198-41-223-194.cloudflare.comIn scope2026-11-14
cf-198-41-223-195.cloudflare.comIn scope2026-11-14
cf-198-41-223-196.cloudflare.comIn scope2026-11-14
cf-198-41-223-197.cloudflare.comIn scope2026-11-14
cf-198-41-223-198.cloudflare.comIn scope2026-11-14
cf-198-41-223-199.cloudflare.comIn scope2026-11-14
cf-198-41-223-20.cloudflare.comIn scope2026-11-14
cf-198-41-223-200.cloudflare.comIn scope2026-11-14
cf-198-41-223-201.cloudflare.comIn scope2026-11-14
cf-198-41-223-202.cloudflare.comIn scope2026-11-14
cf-198-41-223-203.cloudflare.comIn scope2026-11-14
cf-198-41-223-204.cloudflare.comIn scope2026-11-14
cf-198-41-223-205.cloudflare.comIn scope2026-11-14
cf-198-41-223-206.cloudflare.comIn scope2026-11-14
cf-198-41-223-207.cloudflare.comIn scope2026-11-14
cf-198-41-223-208.cloudflare.comIn scope2026-11-14
cf-198-41-223-209.cloudflare.comIn scope2026-11-14
cf-198-41-223-21.cloudflare.comIn scope2026-11-14
cf-198-41-223-210.cloudflare.comIn scope2026-11-14
cf-198-41-223-211.cloudflare.comIn scope2026-11-14
cf-198-41-223-212.cloudflare.comIn scope2026-11-14
cf-198-41-223-213.cloudflare.comIn scope2026-11-14
cf-198-41-223-214.cloudflare.comIn scope2026-11-14
cf-198-41-223-215.cloudflare.comIn scope2026-11-14
cf-198-41-223-216.cloudflare.comIn scope2026-11-14
cf-198-41-223-217.cloudflare.comIn scope2026-11-14
cf-198-41-223-218.cloudflare.comIn scope2026-11-14
cf-198-41-223-219.cloudflare.comIn scope2026-11-14
cf-198-41-223-22.cloudflare.comIn scope2026-11-14
cf-198-41-223-220.cloudflare.comIn scope2026-11-14
cf-198-41-223-221.cloudflare.comIn scope2026-11-14
cf-198-41-223-222.cloudflare.comIn scope2026-11-14
cf-198-41-223-223.cloudflare.comIn scope2026-11-14
cf-198-41-223-224.cloudflare.comIn scope2026-11-14
cf-198-41-223-225.cloudflare.comIn scope2026-11-14
cf-198-41-223-226.cloudflare.comIn scope2026-11-14
cf-198-41-223-227.cloudflare.comIn scope2026-11-14
cf-198-41-223-228.cloudflare.comIn scope2026-11-14
cf-198-41-223-229.cloudflare.comIn scope2026-11-14
cf-198-41-223-23.cloudflare.comIn scope2026-11-14
cf-198-41-223-230.cloudflare.comIn scope2026-11-14
cf-198-41-223-231.cloudflare.comIn scope2026-11-14
cf-198-41-223-232.cloudflare.comIn scope2026-11-14
cf-198-41-223-233.cloudflare.comIn scope2026-11-14
cf-198-41-223-234.cloudflare.comIn scope2026-11-14
cf-198-41-223-235.cloudflare.comIn scope2026-11-14
cf-198-41-223-236.cloudflare.comIn scope2026-11-14
cf-198-41-223-237.cloudflare.comIn scope2026-11-14
cf-198-41-223-238.cloudflare.comIn scope2026-11-14
cf-198-41-223-239.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.