Coinbase cb-mpc

Skip to content What this pays sorona.xyz pays 1.25× the program's reward, up to +$1,000 per finding, plus a complexity bonus of up to $1,000 for especially complex or well-chained bugs. Finding │ Program pays │ Through sorona.xyz Critical (key compromise via signing, DKG or TDH2; the $1M Extreme tier is not applicable to cb-mpc) │ $50,000 │ $51,000 High │ $15,001 │ $16,001 Medium (lower-level cryptographic APIs cap here) │ $2,001 │ $2,501 Low (non-cryptographic code, crashes, deprecated crypto) │ $201 │ $251 Submit a vulnerability CVE history 0 Last 12 months 0 Lifetime Info disclosure 35 % Auth bypass 25 % Parsing/validation 25 % Memory safety 10 % Latest advisories Loading the feed Overview cb-mpc is the production-derived multi-party-computation library behind Coinbase's own custody stack, released under MIT so that other custodians and wallet builders can adopt it. MPC key management is the mechanism by which institutional custody avoids a single point of key compromise, and there are very few production-grade open implementations that put threshold signing, distributed key generation and threshold decryption in one library. Its blast radius is therefore not measured in installs but in assets under custody at every institution that adopts it, plus Coinbase's own holdings, which are among the largest single pools of custodied crypto in existence: a DKG or signing break here is a key-extraction primitive against institutional custody. Coinbase names the open-source library the primary focus of its HackerOne program and pays $50,000 for an easily exploitable high-level protocol break that leads to key compromise: the program's $1,000,000 Extreme tier is marked not applicable to this library, so $50,000 is the real ceiling. sorona.xyz adds 1.25× on top of whatever Coinbase awards, up to $1,000 more, plus a complexity bonus of up to $1,000 for a well-chained finding. In scope github.com/coinbase/cb-mpc , which the program carries as a SOURCE_CODE asset, bounty-eligible and rated up to critical severity, and which Coinbase names the primary focus of the whole program. The declaration is the repository, so the library counts in full rather than only the protocols the reward table names The high-level protocol layer reached through include/cbmpc/api/ : threshold signing, distributed key generation and TDH2 threshold decryption. An easily exploitable break here that leads to key compromise is the $50,000 rung The lower-level cryptographic layer beneath it, including zero-knowledge proofs, commitment schemes and the arithmetic they are built on, priced at the Medium rung Protocol message handling: encoding, decoding and the round state machine that decides which message a party will accept from another The rest of the C++ library, covering non-cryptographic code, crashes and deprecated cryptographic code, which the program pays at the Low rung The wider surface Coinbase declares in the same policy: open-source projects at github.com/coinbase and github.com/base , the .coinbase.com web and API estate, the Coinbase Wallet browser extension and Coinbase WaaS. Of these, only the repositories are open source Out of scope github.com/coinbase/cb-mpc-go , the sibling Go repository, which accepts submissions but is marked bounty-ineligible and pays nothing Proofs of concept that reach the bug through include-internal/ rather than through the public API surface Demo applications, sample code under demo- , and the C API headers under include/cbmpc/c_api/* The $1,000,000 Extreme tier, which the cb-mpc table marks not applicable to this library, so a key compromise here settles at $50,000 Fully AI-generated or automated submissions with no human validation behind them Rate-limiting issues and default security misconfigurations without a demonstrated loss tagomi.com and the other domains the program marks explicitly bounty-ineligible Awards to anyone the program's US sanctions screening blocks, which runs before payment rather than at triage Most-valued findings A protocol-level break in threshold signing, DKG or TDH2 that yields key material or a practical key-extraction primitive, the only class that reaches $50,000 Information disclosure across the protocol transcript or through a side channel that leaks share material to a session participant or an observer A malicious or colluding participant completing an operation the threshold policy should have refused, forging agreement from parties who never signed, or forcing a session into a state the protocol was meant to reject Parsing and validation flaws on attacker-supplied protocol messages arriving through the public API headers Memory safety in the C++ implementation reachable from include/cbmpc/api/ without going through internal headers Program rules Submit through sorona.xyz first. We validate, coordinate with the program's security team, and add the payout uplift on top of whatever it awards. The proof of concept must enter through the public API headers under include/cbmpc/api/ ; one that starts inside include-internal/ is not eligible Demo applications, sample code under demo-* and the C API headers under include/cbmpc/c_api/* sit outside the paid surface Do not price your finding off the $1,000,000 headline: the cb-mpc table marks the Extreme tier not applicable, so $50,000 is the ceiling for this library Fully automated or AI-generated reports with no human validation are closed immediately US sanctions screening applies before any award is paid Give Coinbase a reasonable time to fix before sharing details with anyone else, and request permission to publish through the HackerOne disclosure process Program stats 1,127 Reports resolved $2.88M Bounties paid 83% Response efficiency Disclosure Coordinated through Coinbase on HackerOne under Gold Standard Safe Harbor, with publication requiring Coinbase's permission via the HackerOne disclosure process rather than running on a fixed clock. Because their clause can be read as covering a sorona.xyz-routed report, file directly with Coinbase first and let sorona.xyz follow the report rather than carry it. Safe harbor Sorona will not pursue legal action against you for good-faith research submitted to us in line with this policy. We cannot speak for the upstream project, its vendor, or any third party, and we do not grant authorization on their behalf. You are responsible for understanding and following the laws that apply to you, wherever you are, and for staying within any scope the project has defined. Submit a vulnerability