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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
ssl1.cloudflare.comIn scope2026-11-14
ssl10.cloudflare.comIn scope2026-11-14
ssl11.cloudflare.comIn scope2026-11-14
ssl12.cloudflare.comIn scope2026-11-14
ssl13.cloudflare.comIn scope2026-11-14
ssl14.cloudflare.comIn scope2026-11-14
ssl148594.cloudflare.comIn scope2026-11-14
ssl15.cloudflare.comIn scope2026-11-14
ssl16.cloudflare.comIn scope2026-11-14
ssl17.cloudflare.comIn scope2026-11-14
ssl18.cloudflare.comIn scope2026-11-14
ssl19.cloudflare.comIn scope2026-11-14
ssl2.cloudflare.comIn scope2026-11-14
ssl20.cloudflare.comIn scope2026-11-14
ssl2000.cloudflare.comIn scope2026-11-14
ssl2001.cloudflare.comIn scope2026-11-14
ssl2002.cloudflare.comIn scope2026-11-14
ssl2003.cloudflare.comIn scope2026-11-14
ssl2004.cloudflare.comIn scope2026-11-14
ssl2005.cloudflare.comIn scope2026-11-14
ssl2006.cloudflare.comIn scope2026-11-14
ssl2007.cloudflare.comIn scope2026-11-14
ssl2008.cloudflare.comIn scope2026-11-14
ssl2009.cloudflare.comIn scope2026-11-14
ssl2010.cloudflare.comIn scope2026-11-14
ssl2011.cloudflare.comIn scope2026-11-14
ssl2012.cloudflare.comIn scope2026-11-14
ssl2013.cloudflare.comIn scope2026-11-14
ssl2014.cloudflare.comIn scope2026-11-14
ssl2015.cloudflare.comIn scope2026-11-14
ssl2016.cloudflare.comIn scope2026-11-14
ssl2017.cloudflare.comIn scope2026-11-14
ssl2018.cloudflare.comIn scope2026-11-14
ssl2019.cloudflare.comIn scope2026-11-14
ssl2020.cloudflare.comIn scope2026-11-14
ssl2021.cloudflare.comIn scope2026-11-14
ssl2022.cloudflare.comIn scope2026-11-14
ssl2023.cloudflare.comIn scope2026-11-14
ssl2024.cloudflare.comIn scope2026-11-14
ssl2025.cloudflare.comIn scope2026-11-14
ssl2026.cloudflare.comIn scope2026-11-14
ssl2027.cloudflare.comIn scope2026-11-14
ssl2028.cloudflare.comIn scope2026-11-14
ssl2029.cloudflare.comIn scope2026-11-14
ssl2030.cloudflare.comIn scope2026-11-14
ssl2031.cloudflare.comIn scope2026-11-14
ssl2032.cloudflare.comIn scope2026-11-14
ssl2033.cloudflare.comIn scope2026-11-14
ssl2034.cloudflare.comIn scope2026-11-14
ssl2035.cloudflare.comIn scope2026-11-14
ssl2036.cloudflare.comIn scope2026-11-14
ssl2037.cloudflare.comIn scope2026-11-14
ssl2038.cloudflare.comIn scope2026-11-14
ssl2039.cloudflare.comIn scope2026-11-14
ssl2040.cloudflare.comIn scope2026-11-14
ssl2041.cloudflare.comIn scope2026-11-14
ssl2042.cloudflare.comIn scope2026-11-14
ssl2043.cloudflare.comIn scope2026-11-14
ssl2044.cloudflare.comIn scope2026-11-14
ssl2045.cloudflare.comIn scope2026-11-14
ssl2046.cloudflare.comIn scope2026-11-14
ssl2047.cloudflare.comIn scope2026-11-14
ssl2048.cloudflare.comIn scope2026-11-14
ssl2049.cloudflare.comIn scope2026-11-14
ssl2050.cloudflare.comIn scope2026-11-14
ssl2051.cloudflare.comIn scope2026-11-14
ssl2052.cloudflare.comIn scope2026-11-14
ssl2053.cloudflare.comIn scope2026-11-14
ssl2054.cloudflare.comIn scope2026-11-14
ssl2055.cloudflare.comIn scope2026-11-14
ssl2056.cloudflare.comIn scope2026-11-14
ssl2057.cloudflare.comIn scope2026-11-14
ssl2058.cloudflare.comIn scope2026-11-14
ssl2059.cloudflare.comIn scope2026-11-14
ssl2060.cloudflare.comIn scope2026-11-14
ssl2061.cloudflare.comIn scope2026-11-14
ssl2062.cloudflare.comIn scope2026-11-14
ssl2063.cloudflare.comIn scope2026-11-14
ssl2064.cloudflare.comIn scope2026-11-14
ssl2065.cloudflare.comIn scope2026-11-14
ssl2066.cloudflare.comIn scope2026-11-14
ssl2067.cloudflare.comIn scope2026-11-14
ssl2068.cloudflare.comIn scope2026-11-14
ssl2069.cloudflare.comIn scope2026-11-14
ssl2070.cloudflare.comIn scope2026-11-14
ssl2071.cloudflare.comIn scope2026-11-14
ssl2072.cloudflare.comIn scope2026-11-14
ssl2073.cloudflare.comIn scope2026-11-14
ssl2074.cloudflare.comIn scope2026-11-14
ssl2075.cloudflare.comIn scope2026-11-14
ssl2076.cloudflare.comIn scope2026-11-14
ssl2077.cloudflare.comIn scope2026-11-14
ssl2078.cloudflare.comIn scope2026-11-14
ssl2079.cloudflare.comIn scope2026-11-14
ssl2080.cloudflare.comIn scope2026-11-14
ssl2081.cloudflare.comIn scope2026-11-14
ssl2082.cloudflare.comIn scope2026-11-14
ssl2083.cloudflare.comIn scope2026-11-14
ssl2084.cloudflare.comIn scope2026-11-14
ssl2085.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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