CVE-2026-63761 is a medium-severity (CVSS 4.3) Broken Cryptographic Algorithm vulnerability in surrealdb. A fix is available for surrealdb — see the affected versions and patch details below.
SurrealDB: ES512 silently downgraded to ES384 due to jsonwebtoken crate limitation
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2026-63761.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2026-63761 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 391,411 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
surrealdbReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
When a user configures ALGORITHM ES512 for any JWT access method (DEFINE ACCESS ... TYPE JWT ALGORITHM ES512), SurrealDB silently substitutes ES384 at all four internal algorithm conversion points. This occurs because the underlying jsonwebtoken crate (v10.x) does not include an ES512 algorithm variant, so the mapping defaults to ES384 without raising an error, warning, or log message.
Users who provide the correct P-521 key type for ES512 will experience authentication handshake failures due to the curve mismatch with ES384 (which expects P-384).
Impact
Authentication handshake failures when using ES512 with the correct P-521 key type, and when tokens are verified by external systems expecting real ES512 signatures.
This vulnerability cannot be exploited to forge tokens or compromise the integrity or confidentiality of data handled by SurrealDB, as ES384 remains cryptographically strong.
Patches
Versions prior to SurrealDB v3.1.0 are vulnerable.
The patches for SurrealDB v3.1.0 block new DEFINE ACCESS statements using ALGORITHM ES512 with a clear error message and add deprecation warnings at runtime for existing stored ES512 definitions.
Workarounds
Users should reconfigure affected JWT access methods to use a supported algorithm such as ES384 (with a P-384 key pair) or another supported algorithm. Review any DEFINE ACCESS statements specifying ALGORITHM ES512 and update them accordingly.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | surrealdb | all versions | 3.1.0cargo update -p surrealdb --precise 3.1.0 |
Affected Products
surrealdbsurrealdbDetection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for surrealdb, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update surrealdb to 3.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-63761 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
Frequently Asked Questions
Is CVE-2026-63761 in your dependencies?
Find it across crates.io, including transitive dependencies.