CVE-2026-63761 is a medium-severity (CVSS 4.3) Broken Cryptographic Algorithm vulnerability in surrealdb. O3 Security confirms whether CVE-2026-63761 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
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.
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 | 3.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for surrealdb. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
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.
How O3 protects you
O3 pinpoints whether CVE-2026-63761 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-63761. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-63761 in your dependencies?
O3 detects CVE-2026-63761 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.