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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
ns0238.secondary.cloudflare.comIn scope2026-11-14
ns0239.secondary.cloudflare.comIn scope2026-11-14
ns0240.secondary.cloudflare.comIn scope2026-11-14
ns0241.secondary.cloudflare.comIn scope2026-11-14
ns0242.secondary.cloudflare.comIn scope2026-11-14
ns0243.secondary.cloudflare.comIn scope2026-11-14
ns0244.secondary.cloudflare.comIn scope2026-11-14
ns0245.secondary.cloudflare.comIn scope2026-11-14
ns0246.secondary.cloudflare.comIn scope2026-11-14
ns0247.secondary.cloudflare.comIn scope2026-11-14
ns0248.secondary.cloudflare.comIn scope2026-11-14
ns0249.secondary.cloudflare.comIn scope2026-11-14
ns0250.secondary.cloudflare.comIn scope2026-11-14
ns0251.secondary.cloudflare.comIn scope2026-11-14
ns0252.secondary.cloudflare.comIn scope2026-11-14
secroot.cloudflare.comIn scope2026-11-14
select-config.cloudflare.comIn scope2026-11-14
seo.cloudflare.comIn scope2026-11-14
server.cloudflare.comIn scope2026-11-14
server20423-speedy2.cloudflare.comIn scope2026-11-14
server22730-speedy.cloudflare.comIn scope2026-11-14
server22945-speedy2.cloudflare.comIn scope2026-11-14
ns.seth.cloudflare.comIn scope2026-11-14
sid.cloudflare.comIn scope2026-11-14
it-ps.siwww.cloudflare.comIn scope2026-11-14
sk.cloudflare.comIn scope2026-11-14
sl.cloudflare.comIn scope2026-11-14
cf.44.a80d.ip4.static.sl-173-245-55-99.cloudflare.comIn scope2026-11-14
cf.42.8f0d.ip4.static.sl-reve-50-117.cloudflare.comIn scope2026-11-14
slide.cloudflare.comIn scope2026-11-14
staging.slide.cloudflare.comstagingIn scope2026-11-14
smtp.cloudflare.commailIn scope2026-11-14
sni185369.cloudflare.comIn scope2026-11-14
sol-ix-sto-1500.cloudflare.comIn scope2026-11-14
sol-ix-sto-4470.cloudflare.comIn scope2026-11-14
sparrow.cloudflare.comIn scope2026-11-14
staging.sparrow.cloudflare.comstagingIn scope2026-11-14
worker.staging.sparrow.cloudflare.comstagingIn scope2026-11-14
worker.sparrow.cloudflare.comIn scope2026-11-14
speed.cloudflare.comIn scope2026-11-14
speed-ix.cloudflare.comIn scope2026-11-14
c1.speed.cloudflare.comIn scope2026-11-14
c10.speed.cloudflare.comIn scope2026-11-14
c2.speed.cloudflare.comIn scope2026-11-14
c3.speed.cloudflare.comIn scope2026-11-14
c4.speed.cloudflare.comIn scope2026-11-14
c5.speed.cloudflare.comIn scope2026-11-14
c6.speed.cloudflare.comIn scope2026-11-14
c7.speed.cloudflare.comIn scope2026-11-14
c8.speed.cloudflare.comIn scope2026-11-14
c9.speed.cloudflare.comIn scope2026-11-14
custom-t0.speed.cloudflare.comIn scope2026-11-14
custom-t1.speed.cloudflare.comIn scope2026-11-14
custom-t2.speed.cloudflare.comIn scope2026-11-14
custom-t3.speed.cloudflare.comIn scope2026-11-14
custom-t4.speed.cloudflare.comIn scope2026-11-14
h3.speed.cloudflare.comIn scope2026-11-14
bastion.h3.speed.cloudflare.comIn scope2026-11-14
custom-inside-tunnel.h3.speed.cloudflare.comIn scope2026-11-14
custom-outside-tunnel.h3.speed.cloudflare.comIn scope2026-11-14
production.speed.cloudflare.comIn scope2026-11-14
api.production.speed.cloudflare.comapiIn scope2026-11-14
backoffice.production.speed.cloudflare.comadminIn scope2026-11-14
h3.production.speed.cloudflare.comIn scope2026-11-14
experiment-cca-0.h3.production.speed.cloudflare.comIn scope2026-11-14
experiment-cca-1.h3.production.speed.cloudflare.comIn scope2026-11-14
t0.h3.production.speed.cloudflare.comIn scope2026-11-14
t1.h3.production.speed.cloudflare.comIn scope2026-11-14
t2.h3.production.speed.cloudflare.comIn scope2026-11-14
t3.h3.production.speed.cloudflare.comIn scope2026-11-14
t0.production.speed.cloudflare.comIn scope2026-11-14
t1.production.speed.cloudflare.comIn scope2026-11-14
t2.production.speed.cloudflare.comIn scope2026-11-14
t3.production.speed.cloudflare.comIn scope2026-11-14
staging.speed.cloudflare.comstagingIn scope2026-11-14
api.staging.speed.cloudflare.comapi, stagingIn scope2026-11-14
backoffice.staging.speed.cloudflare.comadmin, stagingIn scope2026-11-14
cors.staging.speed.cloudflare.comstagingIn scope2026-11-14
emdash-cve-test.staging.speed.cloudflare.comstaging, testIn scope2026-11-14
h3.staging.speed.cloudflare.comstagingIn scope2026-11-14
experiment-cca-0.h3.staging.speed.cloudflare.comstagingIn scope2026-11-14
experiment-cca-1.h3.staging.speed.cloudflare.comstagingIn scope2026-11-14
t0.h3.staging.speed.cloudflare.comstagingIn scope2026-11-14
t1.h3.staging.speed.cloudflare.comstagingIn scope2026-11-14
t2.h3.staging.speed.cloudflare.comstagingIn scope2026-11-14
t3.h3.staging.speed.cloudflare.comstagingIn scope2026-11-14
t0.staging.speed.cloudflare.comstagingIn scope2026-11-14
t1.staging.speed.cloudflare.comstagingIn scope2026-11-14
t2.staging.speed.cloudflare.comstagingIn scope2026-11-14
t3.staging.speed.cloudflare.comstagingIn scope2026-11-14
speed2.cloudflare.comIn scope2026-11-14
speedy3.cloudflare.comIn scope2026-11-14
sqlite.cloudflare.comIn scope2026-11-14
admin.sqlite.cloudflare.comadminIn scope2026-11-14
edge.admin.sqlite.cloudflare.comadminIn scope2026-11-14
edge-staging.admin.sqlite.cloudflare.comadmin, stagingIn scope2026-11-14
api.sqlite.cloudflare.comapiIn scope2026-11-14
staging.api.sqlite.cloudflare.comapi, stagingIn scope2026-11-14
dbs-in-dbs.sqlite.cloudflare.comIn scope2026-11-14
sr.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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