{"id":14952,"date":"2026-10-26T22:02:49","date_gmt":"2026-10-26T22:02:49","guid":{"rendered":"https:\/\/cryptonews.uk.com\/?p=14952"},"modified":"2026-10-26T22:02:49","modified_gmt":"2026-10-26T22:02:49","slug":"august-updates-block-critical-private-key-leak-in-crypto-wallet-vultisig","status":"publish","type":"post","link":"https:\/\/cryptonews.uk.com\/?p=14952","title":{"rendered":"August updates block critical private key leak in crypto wallet Vultisig"},"content":{"rendered":"

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Vultisig, a crypto wallet that uses shared signing, mishandled a critical stop signal in its ECDSA signing implementation, as security researchers at ChainSecurity found.<\/p>\n

The researchers\u2019 Oct. 21 disclosure describes how continuing after the error could let one already-compromised signer recover the full private key.<\/p>\n

Both the Android and iOS maintainers described code that retried after the library identified a malicious participant, then added handling to stop those retries and warn the user. The changes appear in subsequent repository release notes.<\/p>\n

Requiring several devices offers protection only if the software preserves that requirement when one participant starts misbehaving.<\/p>\n

A multi-party computation wallet (MPC wallet)\u00a0distributes signing authority among key shares. Enough shares cooperate to produce a standard blockchain signature without assembling the full private key during normal operation.<\/p>\n

In a two-device arrangement requiring both participants, compromising one should leave the attacker dependent on the other device\u2019s approval.<\/p>\n

The disclosed flaw involved ECDSA signing and required that initial compromise. An attacker could then send many malicious signing messages and observe whether the other signer returned an error.<\/p>\n

Those responses revealed bits of a reusable internal protocol seed, eventually enabling recovery of the other share and the full key, according to ChainSecurity.<\/p>\n

That seed is an internal setup secret, and the library assumed further signing would stop after the critical error until the seed was rotated. The application displayed a generic error and did not enforce that response.<\/p>\n

\"Diagram\"Diagram
Vultisig\u2019s historical ECDSA flow could leak key material through repeated error responses; August updates now stop retries and identify the compromised device.<\/figcaption><\/figure>\n

The security consequence is that a failed signing attempt can matter even when it produces no usable transaction signature.<\/p>\n

If continuing the exchange reveals more secret information, rejecting the transaction alone does not preserve the promised separation between signers. The application must respond to the protocol failure itself.<\/p>\n