The Bitcoin / AltCoin Payment Gateway for WooCommerce WordPress plugin before 1.6.1 does not escape the 's' GET parameter before outputting back in the All Masking Rules page, leading to a Reflected Cross-Site Scripting issue

Bitcoin Core 0.12.0 through 0.21.1 does not properly implement the replacement policy specified in BIP125, which makes it easier for attackers to trigger a loss of funds, or a denial of service attack against downstream projects such as Lightning network nodes. An unconfirmed child transaction with nSequence = 0xff_ff_ff_ff, spending an unconfirmed parent with nSequence <= 0xff_ff_ff_fd, should be replaceable because there is inherited signaling by the child transaction. However, the actual PreChecks implementation does not enforce this. Instead, mempool rejects the replacement attempt of the unconfirmed child transaction.

Bitcoin Core before 0.19.0 might allow remote attackers to execute arbitrary code when another application unsafely passes the -platformpluginpath argument to the bitcoin-qt program, as demonstrated by an x-scheme-handler/bitcoin handler for a .desktop file or a web browser. NOTE: the discoverer states "I believe that this vulnerability cannot actually be exploited."

bitcoind in Bitcoin Core through 0.21.0 can create a new file in an arbitrary directory (e.g., outside the ~/.bitcoin directory) via a dumpwallet RPC call. NOTE: this reportedly does not violate the security model of Bitcoin Core, but can violate the security model of a fork that has implemented dumpwallet restrictions

Bitcoin SV before 0.1.1 allows uncontrolled resource consumption when receiving messages with invalid checksums.

Bitcoin SV before 0.1.1 allows uncontrolled resource consumption when receiving sendheaders messages.

Bitcoin SV before 0.1.1 allows uncontrolled resource consumption when deserializing transactions.

Bitcoin Core 0.16.x before 0.16.2 and Bitcoin Knots 0.16.x before 0.16.2 allow remote denial of service via a flood of multiple transaction inv messages with random hashes, aka INVDoS. NOTE: this can also affect other cryptocurrencies, e.g., if they were forked from Bitcoin Core after 2017-11-15.

Bitcoin Core 0.20.0 allows remote denial of service.

Abe (aka bitcoin-abe) through 0.7.2, and 0.8pre, allows XSS in __call__ in abe.py because the PATH_INFO environment variable is mishandled during a PageNotFound exception.