Some sync filters in PowerSync Service ignored using `config.edition: 3`

published 2026-03-07 8 mo ago modified 2026-06-17 4 mo ago also GHSA-q6wc-xx4m-92fj , EUVD-2026-10416

cvss: 6.5; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 14%
public exploits: 0; none known

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.

Patch / fix

fixed in 2

npm @powersync/service-core 1.20.1
npm @powersync/service-sync-rules 0.33.0

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 8 mo ago (2026-03-10)

Exploit prediction

0.23% chance of exploitation in the next 30 days, higher than 14% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
GitHub	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
npm	@powersync/service-core	>=1.20.0, <1.20.1	1.20.1
npm	@powersync/service-sync-rules	>=0.32.0, <0.33.0	0.33.0

Affected products

powersync-ja powersync-service
@powersync service-core
@powersync service-sync-rules

Classification

Weakness

CWE-285 Improper Authorization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary