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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-199-27-134-53.cloudflare.comIn scope2026-11-14
cf-199-27-134-54.cloudflare.comIn scope2026-11-14
cf-199-27-134-55.cloudflare.comIn scope2026-11-14
cf-199-27-134-56.cloudflare.comIn scope2026-11-14
cf-199-27-134-57.cloudflare.comIn scope2026-11-14
cf-199-27-134-58.cloudflare.comIn scope2026-11-14
cf-199-27-134-59.cloudflare.comIn scope2026-11-14
cf-199-27-134-6.cloudflare.comIn scope2026-11-14
cf-199-27-134-60.cloudflare.comIn scope2026-11-14
cf-199-27-134-61.cloudflare.comIn scope2026-11-14
cf-199-27-134-62.cloudflare.comIn scope2026-11-14
cf-199-27-134-63.cloudflare.comIn scope2026-11-14
cf-199-27-134-64.cloudflare.comIn scope2026-11-14
cf-199-27-134-65.cloudflare.comIn scope2026-11-14
cf-199-27-134-66.cloudflare.comIn scope2026-11-14
cf-199-27-134-67.cloudflare.comIn scope2026-11-14
cf-199-27-134-68.cloudflare.comIn scope2026-11-14
cf-199-27-134-69.cloudflare.comIn scope2026-11-14
cf-199-27-134-7.cloudflare.comIn scope2026-11-14
cf-199-27-134-70.cloudflare.comIn scope2026-11-14
cf-199-27-134-71.cloudflare.comIn scope2026-11-14
cf-199-27-134-72.cloudflare.comIn scope2026-11-14
cf-199-27-134-73.cloudflare.comIn scope2026-11-14
cf-199-27-134-74.cloudflare.comIn scope2026-11-14
cf-199-27-134-75.cloudflare.comIn scope2026-11-14
cf-199-27-134-76.cloudflare.comIn scope2026-11-14
cf-199-27-134-77.cloudflare.comIn scope2026-11-14
cf-199-27-134-78.cloudflare.comIn scope2026-11-14
cf-199-27-134-79.cloudflare.comIn scope2026-11-14
cf-199-27-134-8.cloudflare.comIn scope2026-11-14
cf-199-27-134-80.cloudflare.comIn scope2026-11-14
cf-199-27-134-81.cloudflare.comIn scope2026-11-14
cf-199-27-134-82.cloudflare.comIn scope2026-11-14
cf-199-27-134-83.cloudflare.comIn scope2026-11-14
cf-199-27-134-84.cloudflare.comIn scope2026-11-14
cf-199-27-134-85.cloudflare.comIn scope2026-11-14
cf-199-27-134-86.cloudflare.comIn scope2026-11-14
cf-199-27-134-87.cloudflare.comIn scope2026-11-14
cf-199-27-134-88.cloudflare.comIn scope2026-11-14
cf-199-27-134-89.cloudflare.comIn scope2026-11-14
cf-199-27-134-9.cloudflare.comIn scope2026-11-14
cf-199-27-134-90.cloudflare.comIn scope2026-11-14
cf-199-27-134-91.cloudflare.comIn scope2026-11-14
cf-199-27-134-92.cloudflare.comIn scope2026-11-14
cf-199-27-134-93.cloudflare.comIn scope2026-11-14
cf-199-27-134-94.cloudflare.comIn scope2026-11-14
cf-199-27-134-96.cloudflare.comIn scope2026-11-14
cf-199-27-134-97.cloudflare.comIn scope2026-11-14
cf-199-27-134-98.cloudflare.comIn scope2026-11-14
cf-199-27-134-99.cloudflare.comIn scope2026-11-14
cf-199-27-135-100.cloudflare.comIn scope2026-11-14
cf-199-27-135-101.cloudflare.comIn scope2026-11-14
cf-199-27-135-102.cloudflare.comIn scope2026-11-14
cf-199-27-135-103.cloudflare.comIn scope2026-11-14
cf-199-27-135-104.cloudflare.comIn scope2026-11-14
cf-199-27-135-105.cloudflare.comIn scope2026-11-14
cf-199-27-135-106.cloudflare.comIn scope2026-11-14
cf-199-27-135-107.cloudflare.comIn scope2026-11-14
cf-199-27-135-108.cloudflare.comIn scope2026-11-14
cf-199-27-135-109.cloudflare.comIn scope2026-11-14
cf-199-27-135-110.cloudflare.comIn scope2026-11-14
cf-199-27-135-111.cloudflare.comIn scope2026-11-14
cf-199-27-135-112.cloudflare.comIn scope2026-11-14
cf-199-27-135-113.cloudflare.comIn scope2026-11-14
cf-199-27-135-114.cloudflare.comIn scope2026-11-14
cf-199-27-135-115.cloudflare.comIn scope2026-11-14
cf-199-27-135-116.cloudflare.comIn scope2026-11-14
cf-199-27-135-117.cloudflare.comIn scope2026-11-14
cf-199-27-135-118.cloudflare.comIn scope2026-11-14
cf-199-27-135-119.cloudflare.comIn scope2026-11-14
cf-199-27-135-12.cloudflare.comIn scope2026-11-14
cf-199-27-135-120.cloudflare.comIn scope2026-11-14
cf-199-27-135-121.cloudflare.comIn scope2026-11-14
cf-199-27-135-122.cloudflare.comIn scope2026-11-14
cf-199-27-135-123.cloudflare.comIn scope2026-11-14
cf-199-27-135-124.cloudflare.comIn scope2026-11-14
cf-199-27-135-125.cloudflare.comIn scope2026-11-14
cf-199-27-135-126.cloudflare.comIn scope2026-11-14
cf-199-27-135-127.cloudflare.comIn scope2026-11-14
cf-199-27-135-128.cloudflare.comIn scope2026-11-14
cf-199-27-135-129.cloudflare.comIn scope2026-11-14
cf-199-27-135-13.cloudflare.comIn scope2026-11-14
cf-199-27-135-130.cloudflare.comIn scope2026-11-14
cf-199-27-135-131.cloudflare.comIn scope2026-11-14
cf-199-27-135-132.cloudflare.comIn scope2026-11-14
cf-199-27-135-133.cloudflare.comIn scope2026-11-14
cf-199-27-135-134.cloudflare.comIn scope2026-11-14
cf-199-27-135-135.cloudflare.comIn scope2026-11-14
cf-199-27-135-136.cloudflare.comIn scope2026-11-14
cf-199-27-135-137.cloudflare.comIn scope2026-11-14
cf-199-27-135-138.cloudflare.comIn scope2026-11-14
cf-199-27-135-139.cloudflare.comIn scope2026-11-14
cf-199-27-135-14.cloudflare.comIn scope2026-11-14
cf-199-27-135-140.cloudflare.comIn scope2026-11-14
cf-199-27-135-141.cloudflare.comIn scope2026-11-14
cf-199-27-135-142.cloudflare.comIn scope2026-11-14
cf-199-27-135-143.cloudflare.comIn scope2026-11-14
cf-199-27-135-144.cloudflare.comIn scope2026-11-14
cf-199-27-135-145.cloudflare.comIn scope2026-11-14
cf-199-27-135-146.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