Vulnerability · Published Mar 9, 2026 · Assigned by Fluid Attacks

CVE-2026-3089Actual Sync Server 26.2.1 - Authenticated Path Traversal

Medium 5.3

In plain English

A medium-severity path traversal in Actual Sync Server from Actual. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.4% (higher than 36% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 4.0)5.3Medium

Exploit odds (30 days)0.4%top 63.9% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official 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.This issue affects prior versions of Actual Sync Server 26.3.0.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
npm	@actual-app/sync-server	26.3.0	GHSA-27vg-33gh-4hwg

Affected products (as reported)

Vendor	Product	Versions
Actual	Actual Sync Server	26.2.1

Weakness: CWE-22 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N

References

https://fluidattacks.com/advisories/fugue third-party-advisory
https://github.com/actualbudget/actual product
https://github.com/actualbudget/actual/pull/7067 patch