GHSA-Q6WC-XX4M-92FJ

Vulnerability from github – Published: 2026-03-07 02:23 – Updated: 2026-03-23 17:29
VLAI?
Summary
PowerSync: Some sync filters ignored on 1.20.0 using `config.edition: 3`
Details

Impact

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.

Not affected: * Sync rules (bucket_definitions) * Sync streams using config.edition: 2 * No data is exposed without authenticating

Patches

The issue is fixed in 1.20.1. Restarting the service with the new version is sufficient - no reprocessing of sync streams is required.

Any data that users erroneously synced will be automatically removed from those devices when they connect again.

We have updated all affected PowerSync Cloud instances to the fixed version, and are reaching out to affected customers.

For self-hosted PowerSync instances, update to the latest version and restart.

Affected queries

Subqueries used only to determine whether or not a table should be synced (without partitioning the data itself) are affected. Examples:

-- Goal: Sync a table only to admin users
-- 1.20.0: all authenticated users would sync this table
SELECT * FROM sensitive_table WHERE auth.user_id() IN (SELECT user_id FROM admins)
SELECT * FROM sensitive_table WHERE 1 IN (SELECT 1 FROM users WHERE id = auth.user_id() AND is_admin = TRUE)

-- Goal: Sync a table only if authorized
-- 1.20.0: all authenticated users would sync this table
SELECT * FROM sensitive_table WHERE 'sensitive_table' IN (SELECT table_name FROM synced_table WHERE "user" = auth.user_id())
SELECT * FROM sensitive_table WHERE 'sensitive_table' IN auth.parameter('allowed_tables')

Queries that partition data (for example SELECT * FROM sensitive_table WHERE owner IN (SELECT id FROM users WHERE is_admin AND id = auth.user_id())) are not affected by this issue.

Severity ?
6.5 (Medium)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Show details on source website
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@powersync/service-core"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.20.0"
            },
            {
              "fixed": "1.20.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.20.0"
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@powersync/service-sync-rules"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.32.0"
            },
            {
              "fixed": "0.33.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.32.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-30870"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-285"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-03-07T02:23:24Z",
    "nvd_published_at": "2026-03-10T17:40:14Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nIn 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.\n\nDepending on the sync stream configuration, this could result in authenticated users syncing data that should have been restricted.\n\nOnly queries that gate synchronization using subqueries without partitioning the result set are affected.\n\nNot affected:\n * Sync rules (bucket_definitions)\n * Sync streams using `config.edition: 2`\n * No data is exposed without authenticating\n\n### Patches\n\nThe issue is **fixed in 1.20.1**. Restarting the service with the new version is sufficient - no reprocessing of sync streams is required.\n\nAny data that users erroneously synced will be automatically removed from those devices when they connect again.\n\nWe have updated all affected PowerSync Cloud instances to the fixed version, and are reaching out to affected customers.\n\nFor self-hosted PowerSync instances, update to the latest version and restart.\n\n### Affected queries\n\nSubqueries used only to determine whether or not a table should be synced (without partitioning the data itself) are affected. Examples:\n\n```sql\n-- Goal: Sync a table only to admin users\n-- 1.20.0: all authenticated users would sync this table\nSELECT * FROM sensitive_table WHERE auth.user_id() IN (SELECT user_id FROM admins)\nSELECT * FROM sensitive_table WHERE 1 IN (SELECT 1 FROM users WHERE id = auth.user_id() AND is_admin = TRUE)\n\n-- Goal: Sync a table only if authorized\n-- 1.20.0: all authenticated users would sync this table\nSELECT * FROM sensitive_table WHERE \u0027sensitive_table\u0027 IN (SELECT table_name FROM synced_table WHERE \"user\" = auth.user_id())\nSELECT * FROM sensitive_table WHERE \u0027sensitive_table\u0027 IN auth.parameter(\u0027allowed_tables\u0027)\n```\n\nQueries that partition data (for example `SELECT * FROM sensitive_table WHERE owner IN (SELECT id FROM users WHERE is_admin AND id = auth.user_id())`) are not affected by this issue.",
  "id": "GHSA-q6wc-xx4m-92fj",
  "modified": "2026-03-23T17:29:15Z",
  "published": "2026-03-07T02:23:24Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/powersync-ja/powersync-service/security/advisories/GHSA-q6wc-xx4m-92fj"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-30870"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/powersync-ja/powersync-service"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "PowerSync: Some sync filters ignored on 1.20.0 using `config.edition: 3`"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.