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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-199-27-128-103.cloudflare.comIn scope2026-11-14
cf-199-27-128-104.cloudflare.comIn scope2026-11-14
cf-199-27-128-105.cloudflare.comIn scope2026-11-14
cf-199-27-128-106.cloudflare.comIn scope2026-11-14
cf-199-27-128-107.cloudflare.comIn scope2026-11-14
cf-199-27-128-108.cloudflare.comIn scope2026-11-14
cf-199-27-128-109.cloudflare.comIn scope2026-11-14
cf-199-27-128-11.cloudflare.comIn scope2026-11-14
cf-199-27-128-110.cloudflare.comIn scope2026-11-14
cf-199-27-128-111.cloudflare.comIn scope2026-11-14
cf-199-27-128-112.cloudflare.comIn scope2026-11-14
cf-199-27-128-113.cloudflare.comIn scope2026-11-14
cf-199-27-128-114.cloudflare.comIn scope2026-11-14
cf-199-27-128-115.cloudflare.comIn scope2026-11-14
cf-199-27-128-116.cloudflare.comIn scope2026-11-14
cf-199-27-128-117.cloudflare.comIn scope2026-11-14
cf-199-27-128-118.cloudflare.comIn scope2026-11-14
cf-199-27-128-119.cloudflare.comIn scope2026-11-14
cf-199-27-128-12.cloudflare.comIn scope2026-11-14
cf-199-27-128-120.cloudflare.comIn scope2026-11-14
cf-199-27-128-121.cloudflare.comIn scope2026-11-14
cf-199-27-128-122.cloudflare.comIn scope2026-11-14
cf-199-27-128-123.cloudflare.comIn scope2026-11-14
cf-199-27-128-124.cloudflare.comIn scope2026-11-14
cf-199-27-128-125.cloudflare.comIn scope2026-11-14
cf-199-27-128-126.cloudflare.comIn scope2026-11-14
cf-199-27-128-127.cloudflare.comIn scope2026-11-14
cf-199-27-128-128.cloudflare.comIn scope2026-11-14
cf-199-27-128-129.cloudflare.comIn scope2026-11-14
cf-199-27-128-13.cloudflare.comIn scope2026-11-14
cf-199-27-128-130.cloudflare.comIn scope2026-11-14
cf-199-27-128-131.cloudflare.comIn scope2026-11-14
cf-199-27-128-132.cloudflare.comIn scope2026-11-14
cf-199-27-128-133.cloudflare.comIn scope2026-11-14
cf-199-27-128-134.cloudflare.comIn scope2026-11-14
cf-199-27-128-135.cloudflare.comIn scope2026-11-14
cf-199-27-128-136.cloudflare.comIn scope2026-11-14
cf-199-27-128-137.cloudflare.comIn scope2026-11-14
cf-199-27-128-138.cloudflare.comIn scope2026-11-14
cf-199-27-128-139.cloudflare.comIn scope2026-11-14
cf-199-27-128-14.cloudflare.comIn scope2026-11-14
cf-199-27-128-140.cloudflare.comIn scope2026-11-14
cf-199-27-128-141.cloudflare.comIn scope2026-11-14
cf-199-27-128-142.cloudflare.comIn scope2026-11-14
cf-199-27-128-143.cloudflare.comIn scope2026-11-14
cf-199-27-128-144.cloudflare.comIn scope2026-11-14
cf-199-27-128-145.cloudflare.comIn scope2026-11-14
cf-199-27-128-146.cloudflare.comIn scope2026-11-14
cf-199-27-128-147.cloudflare.comIn scope2026-11-14
cf-199-27-128-148.cloudflare.comIn scope2026-11-14
cf-199-27-128-149.cloudflare.comIn scope2026-11-14
cf-199-27-128-15.cloudflare.comIn scope2026-11-14
cf-199-27-128-150.cloudflare.comIn scope2026-11-14
cf-199-27-128-151.cloudflare.comIn scope2026-11-14
cf-199-27-128-152.cloudflare.comIn scope2026-11-14
cf-199-27-128-153.cloudflare.comIn scope2026-11-14
cf-199-27-128-154.cloudflare.comIn scope2026-11-14
cf-199-27-128-155.cloudflare.comIn scope2026-11-14
cf-199-27-128-156.cloudflare.comIn scope2026-11-14
cf-199-27-128-157.cloudflare.comIn scope2026-11-14
cf-199-27-128-158.cloudflare.comIn scope2026-11-14
cf-199-27-128-159.cloudflare.comIn scope2026-11-14
cf-199-27-128-16.cloudflare.comIn scope2026-11-14
cf-199-27-128-160.cloudflare.comIn scope2026-11-14
cf-199-27-128-161.cloudflare.comIn scope2026-11-14
cf-199-27-128-162.cloudflare.comIn scope2026-11-14
cf-199-27-128-163.cloudflare.comIn scope2026-11-14
cf-199-27-128-164.cloudflare.comIn scope2026-11-14
cf-199-27-128-165.cloudflare.comIn scope2026-11-14
cf-199-27-128-166.cloudflare.comIn scope2026-11-14
cf-199-27-128-167.cloudflare.comIn scope2026-11-14
cf-199-27-128-168.cloudflare.comIn scope2026-11-14
cf-199-27-128-169.cloudflare.comIn scope2026-11-14
cf-199-27-128-170.cloudflare.comIn scope2026-11-14
cf-199-27-128-171.cloudflare.comIn scope2026-11-14
cf-199-27-128-172.cloudflare.comIn scope2026-11-14
cf-199-27-128-173.cloudflare.comIn scope2026-11-14
cf-199-27-128-174.cloudflare.comIn scope2026-11-14
cf-199-27-128-175.cloudflare.comIn scope2026-11-14
cf-199-27-128-176.cloudflare.comIn scope2026-11-14
cf-199-27-128-177.cloudflare.comIn scope2026-11-14
cf-199-27-128-178.cloudflare.comIn scope2026-11-14
cf-199-27-128-179.cloudflare.comIn scope2026-11-14
cf-199-27-128-18.cloudflare.comIn scope2026-11-14
cf-199-27-128-180.cloudflare.comIn scope2026-11-14
cf-199-27-128-181.cloudflare.comIn scope2026-11-14
cf-199-27-128-182.cloudflare.comIn scope2026-11-14
cf-199-27-128-183.cloudflare.comIn scope2026-11-14
cf-199-27-128-184.cloudflare.comIn scope2026-11-14
cf-199-27-128-185.cloudflare.comIn scope2026-11-14
cf-199-27-128-186.cloudflare.comIn scope2026-11-14
cf-199-27-128-187.cloudflare.comIn scope2026-11-14
cf-199-27-128-188.cloudflare.comIn scope2026-11-14
cf-199-27-128-189.cloudflare.comIn scope2026-11-14
cf-199-27-128-19.cloudflare.comIn scope2026-11-14
cf-199-27-128-190.cloudflare.comIn scope2026-11-14
cf-199-27-128-191.cloudflare.comIn scope2026-11-14
cf-199-27-128-192.cloudflare.comIn scope2026-11-14
cf-199-27-128-193.cloudflare.comIn scope2026-11-14
cf-199-27-128-194.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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