Vulnerability 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.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Surrealdb | Surrealdb | < 3.1.0 |
Related Weaknesses (CWE)
References
- https://github.com/surrealdb/surrealdb/security/advisories/GHSA-fwg2-gr34-q3w8Vendor AdvisoryMitigation
- https://www.vulncheck.com/advisories/surrealdb-before-algorithm-downgrade-via-esThird Party Advisory
FAQ
What is CVE-2026-63761?
CVE-2026-63761 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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 jsonweb...
How severe is CVE-2026-63761?
CVE-2026-63761 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-63761?
Check the references section above for vendor advisories and patch information. Affected products include: Surrealdb Surrealdb.