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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
ssl2086.cloudflare.comIn scope2026-11-14
ssl2087.cloudflare.comIn scope2026-11-14
ssl2088.cloudflare.comIn scope2026-11-14
ssl2089.cloudflare.comIn scope2026-11-14
ssl2090.cloudflare.comIn scope2026-11-14
ssl2091.cloudflare.comIn scope2026-11-14
ssl2092.cloudflare.comIn scope2026-11-14
ssl2093.cloudflare.comIn scope2026-11-14
ssl2094.cloudflare.comIn scope2026-11-14
ssl2095.cloudflare.comIn scope2026-11-14
ssl2096.cloudflare.comIn scope2026-11-14
ssl2097.cloudflare.comIn scope2026-11-14
ssl2098.cloudflare.comIn scope2026-11-14
ssl2099.cloudflare.comIn scope2026-11-14
ssl21.cloudflare.comIn scope2026-11-14
ssl2100.cloudflare.comIn scope2026-11-14
ssl2101.cloudflare.comIn scope2026-11-14
ssl2102.cloudflare.comIn scope2026-11-14
ssl2103.cloudflare.comIn scope2026-11-14
ssl2104.cloudflare.comIn scope2026-11-14
ssl2105.cloudflare.comIn scope2026-11-14
ssl2106.cloudflare.comIn scope2026-11-14
ssl2107.cloudflare.comIn scope2026-11-14
ssl2108.cloudflare.comIn scope2026-11-14
ssl2109.cloudflare.comIn scope2026-11-14
ssl2110.cloudflare.comIn scope2026-11-14
ssl2111.cloudflare.comIn scope2026-11-14
ssl2112.cloudflare.comIn scope2026-11-14
ssl2113.cloudflare.comIn scope2026-11-14
ssl2114.cloudflare.comIn scope2026-11-14
ssl2115.cloudflare.comIn scope2026-11-14
ssl2116.cloudflare.comIn scope2026-11-14
ssl2117.cloudflare.comIn scope2026-11-14
ssl2118.cloudflare.comIn scope2026-11-14
ssl2119.cloudflare.comIn scope2026-11-14
ssl2120.cloudflare.comIn scope2026-11-14
ssl2121.cloudflare.comIn scope2026-11-14
ssl2122.cloudflare.comIn scope2026-11-14
ssl2123.cloudflare.comIn scope2026-11-14
ssl2124.cloudflare.comIn scope2026-11-14
ssl2125.cloudflare.comIn scope2026-11-14
ssl2126.cloudflare.comIn scope2026-11-14
ssl2127.cloudflare.comIn scope2026-11-14
ssl2128.cloudflare.comIn scope2026-11-14
ssl2129.cloudflare.comIn scope2026-11-14
ssl2130.cloudflare.comIn scope2026-11-14
ssl2131.cloudflare.comIn scope2026-11-14
ssl2132.cloudflare.comIn scope2026-11-14
ssl2133.cloudflare.comIn scope2026-11-14
ssl2134.cloudflare.comIn scope2026-11-14
ssl2135.cloudflare.comIn scope2026-11-14
ssl2136.cloudflare.comIn scope2026-11-14
ssl2137.cloudflare.comIn scope2026-11-14
ssl2138.cloudflare.comIn scope2026-11-14
ssl2139.cloudflare.comIn scope2026-11-14
ssl2140.cloudflare.comIn scope2026-11-14
ssl2141.cloudflare.comIn scope2026-11-14
ssl2142.cloudflare.comIn scope2026-11-14
ssl2143.cloudflare.comIn scope2026-11-14
ssl2144.cloudflare.comIn scope2026-11-14
ssl2145.cloudflare.comIn scope2026-11-14
ssl2146.cloudflare.comIn scope2026-11-14
ssl2147.cloudflare.comIn scope2026-11-14
ssl2148.cloudflare.comIn scope2026-11-14
ssl2149.cloudflare.comIn scope2026-11-14
ssl2150.cloudflare.comIn scope2026-11-14
ssl2151.cloudflare.comIn scope2026-11-14
ssl2152.cloudflare.comIn scope2026-11-14
ssl2153.cloudflare.comIn scope2026-11-14
ssl2154.cloudflare.comIn scope2026-11-14
ssl2155.cloudflare.comIn scope2026-11-14
ssl2156.cloudflare.comIn scope2026-11-14
ssl2157.cloudflare.comIn scope2026-11-14
ssl2158.cloudflare.comIn scope2026-11-14
ssl2159.cloudflare.comIn scope2026-11-14
ssl2160.cloudflare.comIn scope2026-11-14
ssl2161.cloudflare.comIn scope2026-11-14
ssl2162.cloudflare.comIn scope2026-11-14
ssl2163.cloudflare.comIn scope2026-11-14
ssl2164.cloudflare.comIn scope2026-11-14
ssl2165.cloudflare.comIn scope2026-11-14
ssl2166.cloudflare.comIn scope2026-11-14
ssl2167.cloudflare.comIn scope2026-11-14
ssl2168.cloudflare.comIn scope2026-11-14
ssl2169.cloudflare.comIn scope2026-11-14
ssl2170.cloudflare.comIn scope2026-11-14
ssl2171.cloudflare.comIn scope2026-11-14
ssl2172.cloudflare.comIn scope2026-11-14
ssl2173.cloudflare.comIn scope2026-11-14
ssl2174.cloudflare.comIn scope2026-11-14
ssl2175.cloudflare.comIn scope2026-11-14
ssl2176.cloudflare.comIn scope2026-11-14
ssl2177.cloudflare.comIn scope2026-11-14
ssl2178.cloudflare.comIn scope2026-11-14
ssl2179.cloudflare.comIn scope2026-11-14
ssl2180.cloudflare.comIn scope2026-11-14
ssl2181.cloudflare.comIn scope2026-11-14
ssl2182.cloudflare.comIn scope2026-11-14
ssl2183.cloudflare.comIn scope2026-11-14
ssl2184.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.