CVE-2026-30870 — MEDIUM (6.5)

Vulnerability Description

PowerSync Service is the server-side component of the PowerSync sync engine. In version 1.20.0, when using new sync streams with config.edition: 3, certain subquery filters were ignored when determining which data to sync to users. Depending on the sync stream configuration, this could result in authenticated users syncing data that should have been restricted. Only queries that gate synchronization using subqueries without partitioning the result set are affected. This vulnerability is fixed in 1.20.1.

CVSS Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality

HIGH

Integrity

NONE

Availability

NONE

Related Weaknesses (CWE)

CWE-285

References

https://github.com/powersync-ja/powersync-service/security/advisories/GHSA-q6wc-

FAQ

What is CVE-2026-30870?

CVE-2026-30870 is a vulnerability with a CVSS score of 6.5 (MEDIUM). PowerSync Service is the server-side component of the PowerSync sync engine. In version 1.20.0, when using new sync streams with config.edition: 3, certain subquery filters were ignored when determini...

How severe is CVE-2026-30870?

CVE-2026-30870 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-30870?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.