GHSA-gcwr-5mrf-fvch CVE-2026-63758
SurrealDB: Authorization Bypass in KILL Statement Allows Termination of Other Users' Live Queries
- Severity
- 5.3 / 10
- Medium · CVSS 4.0
- Exploit chance (EPSS)
- 0.31%
- Chance of exploitation in the next 30 days. Higher than 23.80% of scored vulnerabilities.
- Known exploited
- No
- Not in CISA's catalog
- Weakness
- CWE-862 Missing Authorization
- Fix
3.1.0- Upgrade surrealdb to this version or later
Description
The KILL statement is used to terminate LIVE SELECT subscriptions that capture real-time changes to data within a table. The KILL statement implementation in core/src/expr/statements/kill.rs verifies that the requesting user has database-level access, but does not verify that the requesting user is the owner of the live query being terminated.
After passing the valid_for_db() check, the KILL statement resolves the live query UUID, looks up the corresponding live query entry, and immediately deletes it without comparing the requesting user's identity against the live query owner. This allows any authenticated user with database-level access to terminate any live query in that database, regardless of who created it.
The affected user's real-time subscription silently stops receiving updates with no notification that the live query was terminated. The same attack works across privilege levels: a low-privilege record-scoped user can terminate a root user's monitoring live queries.
This issue was discovered and patched during a code audit and penetration test of SurrealDB by cure53, the severity defined within cure53's preliminary finding is Medium, matched by our CVSS v3.1 assessment.
Impact
An authenticated user with database-level access can terminate any other user's live query subscriptions within the same database by issuing a KILL statement with the target live query's UUID. This impacts availability by silently disrupting real-time data subscriptions and breaks multi-tenant isolation guarantees.
The attack requires knowledge of the target live query UUID. Live query UUIDs are randomly generated, but may be exposed through application logs, shared monitoring dashboards, or other information disclosure vectors.
Patches
An ownership verification check has been introduced in the KILL statement implementation that compares the requesting user's authentication context against the owner of the live query before allowing deletion.
- Versions 3.1.0 and later are not affected by this issue.
Workarounds
Users unable to upgrade should consider the following mitigations:
- Ensure that live query UUIDs are treated as sensitive values and are not exposed to other users through application logs, error messages, or shared interfaces.
- Where multi-tenant isolation is critical, use separate databases per tenant rather than relying on record-level access controls within a shared database.
- Monitor for unexpected termination of live queries in application logic and implement reconnection and re-subscription mechanisms.
Affected versions
crates.io
| Package | Vulnerable | Fixed in |
|---|---|---|
| surrealdb | < 3.1.0 |
3.1.0 |
How to fix
Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.
surrealdb crates.io → 3.1.0
- cargo
cargo update -p surrealdb --precise 3.1.0
Severity breakdown
CVSS 4.0 5.3
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
- Attack vector
- Network
- Attack complexity
- Low
- Attack requirements
- None
- Privileges required
- Low
- User interaction
- None
- Confidentiality (vulnerable system)
- None
- Integrity (vulnerable system)
- Low
- Availability (vulnerable system)
- Low
- Confidentiality (subsequent systems)
- None
- Integrity (subsequent systems)
- None
- Availability (subsequent systems)
- None
- Exploit maturity
- Not defined
- Scope
- X
CVSS 3.1 5.4
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:L
- Attack vector
- Network
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- Low
Weakness
CWE-862: Missing Authorization
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.
How to prevent it
- Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
- Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
- Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
- Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
- System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.
References
Advisories
Packages
Other links
Timeline
- Published
- Last updated by the source
- Latest EPSS score
Related advisories
| Advisory | Severity | Why it's related |
|---|---|---|
| GHSA-8rw6-p7m8-63jp SurrealDB: Array element-level (field.*) SELECT permissions leak denied elements to record users | High | Also affects surrealdb |
| GHSA-848m-r628-vrxw SurrealDB: Custom API route lets authenticated callers override namespace/database scope via URL path | High | Also affects surrealdb |
| GHSA-m3c3-78fh-w3w7 SurrealDB allows bypass of deny-net flags via DNS resolution | High | Also affects SurrealDB |
| GHSA-whwg-vh4f-pmmf SurrealDB: Edge PERMISSIONS FOR delete bypassed when a connected node is deleted | Medium | Also affects surrealdb |
| GHSA-fwg2-gr34-q3w8 SurrealDB: ES512 silently downgraded to ES384 due to jsonwebtoken crate limitation | Medium | Also affects surrealdb |
| GHSA-c8jx-96c9-8xrp SurrealDB: Field-level SELECT permissions bypassed via indexed COUNT fast paths | Medium | Also affects surrealdb |
| GHSA-wp87-mgvq-5j93 SurrealDB: USE NS/DB implicit creation bypasses DEFINE authorization | Medium | Also affects surrealdb |
| GHSA-97vg-427p-8hx5 SurrealDB: Port-specific --deny-net rules silently bypassed on HTTP redirect | Medium | Also affects surrealdb |
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