CVE-2026-3089 PUBLISHED

Actual Sync Server 26.2.1 - Authenticated Path Traversal

Assigner: Fluid Attacks
Reserved: 24.02.2026 Published: 09.03.2026 Updated: 09.03.2026

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.

Metrics

CVSS 4.0

CVSS 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
CVSS Score: 5.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	Low	Integrity	Low	Integrity	None
Attack Requirements	None	Availability	None	Availability	None
Privileges Required	Low
User Interaction	None

CVSS 4.0

Product Status

Vendor	Actual
Product	Actual Sync Server
Versions	Default: unaffected Version 26.2.1 is affected

Credits

Juan Patarroyo finder

References

Problem Types

CWE-22 Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal') CWE

Impacts

CAPEC-126 Path Traversal