CVE-2026-63761
Received Received - Intake

SurrealDB JWT ES512 Algorithm Substitution Weakness

Publication date: 2026-07-20

Last updated on: 2026-07-20

Assigner: VulnCheck

Description
SurrealDB before 3.1.0 silently substitutes the ES384 algorithm when a JWT access method is configured with ALGORITHM ES512 (DEFINE ACCESS ... TYPE JWT ALGORITHM ES512), because the underlying jsonwebtoken crate (v10.x) has no ES512 variant and the mapping defaults to ES384 without any error, warning, or log message. Users who supply the correct P-521 key for ES512 experience authentication handshake failures due to the curve mismatch with ES384 (which expects P-384), and tokens are rejected by external systems expecting genuine ES512 signatures. The flaw cannot be used to forge tokens or compromise data confidentiality or integrity, as ES384 remains cryptographically strong.

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Meta Information

Published
2026-07-20
Last Modified
2026-07-20
Generated
2026-07-21
AI Q&A
2026-07-20
EPSS Evaluated
N/A
NVD
CVE-2026-63761
EUVD
EUVD-2026-45932

Affected Vendors & Products

Showing 2 associated CPEs
Vendor Product Version / Range
surrealdb surrealdb to 3.1.0 (exc)
jsonwebtoken jsonwebtoken 10.*

Helpful Resources

Exploitability

CWE
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KEV
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CWE ID Description
CWE-327 The product uses a broken or risky cryptographic algorithm or protocol.

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Executive Summary

SurrealDB before version 3.1.0 silently downgrades the ES512 JWT algorithm to ES384 due to a limitation in the jsonwebtoken crate (v10.x), which lacks ES512 support. This happens without any error, warning, or log message when users configure JWT access methods with ALGORITHM ES512.

Detection Guidance

Check SurrealDB version with 'surreal version' command. If version is below 3.1.0, the system is vulnerable. Inspect JWT access configurations for ALGORITHM ES512 using 'DEFINE ACCESS' queries. Monitor authentication failures in logs that may indicate algorithm mismatch.

Impact Analysis

Users providing a P-521 key for ES512 will face authentication failures because ES384 expects a P-384 key. Tokens may be rejected by external systems expecting valid ES512 signatures. The issue causes failed authentication handshakes but does not allow token forgery or compromise of data integrity or confidentiality.

Compliance Impact

This vulnerability does not directly compromise data confidentiality or integrity, as ES384 remains cryptographically strong. However, failed authentication handshakes due to algorithm mismatch could disrupt access controls, potentially impacting compliance with standards like GDPR or HIPAA that require reliable authentication mechanisms.

Mitigation Strategies

Upgrade SurrealDB to version 3.1.0 or later. Reconfigure affected JWT access methods to use supported algorithms like ES384 instead of ES512. Review and update external systems expecting ES512 signatures to accept ES384 tokens.

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