@actual-app/sync-server

CVE-2026-3089

CVE-2026-3089 is a medium-severity path traversal vulnerability in @actual-app/sync-server (npm), affecting versions <= 26.2.0. It is fixed in 26.3.0.

Key facts
CVSS score
N/A
Medium
Attack vector
Not available
Issuing authority
GitHub Advisory Database
Affected package
@actual-app/sync-server
Fixed in
26.3.0
Disclosed
2026

Summary

Description Actual Sync Server allows authenticated users to upload files through POST /sync/upload-user-file. In versions prior to 26.3.0, improper validation of the user-controlled x-actual-file-id header means that traversal segments (../) can escape the intended directory and write files outside userFiles. Mitigations The vulnerability can be mitigated in prior versions by running the sync server in a filesystem sandbox.

Impact

What is path traversal?

Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files. Typical impact: unauthorized file read or write outside the intended directory.

Affected versions

npm

  • @actual-app/sync-server (<= 26.2.0)

Security releases

  • @actual-app/sync-server → 26.3.0 (npm)
Kodem intelligence

Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.

Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter instead of chasing every advisory.

Kodem's runtime-powered SCA identifies whether CVE-2026-3089 is reachable in your applications. Explore open-source security for your team.

See if CVE-2026-3089 is reachable in your applications. Get a demo

Already deployed Kodem? See CVE-2026-3089 in your environment

Remediation advice

Upgrade @actual-app/sync-server to 26.3.0 or later to resolve this vulnerability.

Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.

Frequently asked questions about CVE-2026-3089

What is CVE-2026-3089?

CVE-2026-3089 is a medium-severity path traversal vulnerability in @actual-app/sync-server (npm), affecting versions <= 26.2.0. It is fixed in 26.3.0. Input manipulates file paths to reach files outside the intended directory, such as configuration or credential files.

Which versions of @actual-app/sync-server are affected by CVE-2026-3089?

@actual-app/sync-server (npm) versions <= 26.2.0 is affected.

Is there a fix for CVE-2026-3089?

Yes. CVE-2026-3089 is fixed in 26.3.0. Upgrade to this version or later.

Is CVE-2026-3089 exploitable, and should I be worried?

Whether CVE-2026-3089 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo

What actually determines whether CVE-2026-3089 is exploitable, and how bad it is?

Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.

How do I fix CVE-2026-3089?

Upgrade @actual-app/sync-server to 26.3.0 or later.

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