CVE-2025-69287: The BSV Blockchain SDK is a unified TypeScript SDK for developing scalable apps on the BSV Blockchain. Prior to version 2.0.0, a cryptographic vulnera...

Description

The BSV Blockchain SDK is a unified TypeScript SDK for developing scalable apps on the BSV Blockchain. Prior to version 2.0.0, a cryptographic vulnerability in the TypeScript SDK's BRC-104 authentication implementation caused incorrect signature data preparation, resulting in signature incompatibility between SDK implementations and potential authentication bypass scenarios. The vulnerability was located in the `Peer.ts` file of the TypeScript SDK, specifically in the `processInitialRequest` and `processInitialResponse` methods where signature data is prepared for BRC-104 mutual authentication. The TypeScript SDK incorrectly prepared signature data by concatenating base64-encoded nonce strings (`message.initialNonce + sessionNonce`) then decoding the concatenated base64 string (`base64ToBytes(concatenatedString)`). This produced ~32-34 bytes of signature data instead of the correct 64 bytes. BRC-104 authentication relies on cryptographic signatures to establish mutual trust between peers. When signature data preparation is incorrect, signatures generated by the TypeScript SDK don't match those expected by Go/Python SDKs; cross-implementation authentication fails; and an attacker could potentially exploit this to bypass authentication checks. The fix in version 2.0.0 ensures all SDKs now produce identical cryptographic signatures, restoring proper mutual authentication across implementations.

Metrics

CVSS 3.1

5.4/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:L

EPSS Probability

0.29%

20.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-573

References

Timeline

Published: Feb 18, 2026
Last Modified: Jun 17, 2026
Status: Deferred

Frequently Asked Questions

What is CVE-2025-69287?

The BSV Blockchain SDK is a unified TypeScript SDK for developing scalable apps on the BSV Blockchain. Prior to version 2.0.0, a cryptographic vulnerability in the TypeScript SDK's BRC-104 authentication implementation caused incorrect signature data preparation, resulting in signature incompatibility between SDK implementations and potential authentication bypass scenarios. The vulnerability was located in the `Peer.ts` file of the TypeScript SDK, specifically in the `processInitialRequest` and `processInitialResponse` methods where signature data is prepared for BRC-104 mutual authentication. The TypeScript SDK incorrectly prepared signature data by concatenating base64-encoded nonce strings (`message.initialNonce + sessionNonce`) then decoding the concatenated base64 string (`base64ToBytes(concatenatedString)`). This produced ~32-34 bytes of signature data instead of the correct 64 bytes. BRC-104 authentication relies on cryptographic signatures to establish mutual trust between peers. When signature data preparation is incorrect, signatures generated by the TypeScript SDK don't match those expected by Go/Python SDKs; cross-implementation authentication fails; and an attacker could potentially exploit this to bypass authentication checks. The fix in version 2.0.0 ensures all SDKs now produce identical cryptographic signatures, restoring proper mutual authentication across implementations.

How severe is CVE-2025-69287?

CVE-2025-69287 has a CVSS score of 5.4/10 (MEDIUM severity). The EPSS model estimates a 0.29% probability of exploitation in the next 30 days.

How do I fix CVE-2025-69287?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.