Authentication failure via truncated nonce signature data
Published Feb 18, 2026 · Updated Feb 18, 2026
Cryptographic signing error in BSV Blockchain bsv-sdk before 2.0.0 allows remote attackers to disrupt cross-SDK BRC-104 authentication. Peer.ts processInitialRequest and processInitialResponse concatenate two base64 nonce strings before decoding, so padding stops decoding after about 32 bytes instead of producing the required 64. Reachability requires an application to use BRC-104 mutual authentication and user interaction; the demonstrated consequence is failed TypeScript-to-Go or TypeScript-to-Python authentication, while bypass depends on an application ignoring verification failure.
Summary
What happened
Cryptographic signing error in BSV Blockchain bsv-sdk before 2.0.0 allows remote attackers to disrupt cross-SDK BRC-104 authentication. Peer.ts processInitialRequest and processInitialResponse concatenate two base64 nonce strings before decoding, so padding stops decoding after about 32 bytes instead of producing the required 64. Reachability requires an application to use BRC-104 mutual authentication and user interaction; the demonstrated consequence is failed TypeScript-to-Go or TypeScript-to-Python authentication, while bypass depends on an application ignoring verification failure.
The record
- CVE
- CVE-2025-69287
- Published
- Feb 18, 2026
- Updated
- Feb 18, 2026
- Vendor
- BSV Blockchain
- Product
- bsv-sdk
- Classifications
- CWE-573
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Feb 18, 2026CVE publishedPublication date reported by the CVE source.
- Feb 18, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 2.0.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Cross-language BRC-104 signature preparation PoCproof of concept · demonstrated
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Technologies
Your stack
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Your stack
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