What is CVE-2025-29843?

CVE-2025-29843 is a medium-severity vulnerability in Synology Router Manager, classified under Path Traversal. CVSS score: 5.4/10. Published 2025-12-04.

How severe is CVE-2025-29843?

Medium severity. CVSS v3 base score is 5.4 out of 10.

Path Traversal in Synology Router Manager

CVE-2025-29843

A vulnerability in FileStation thumb cgi allows remote authenticated users to read/write image files.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2025-12-04 · last modified 2026-09-25.

CVSS v3 metric

CVSS v3 base score 5.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.004 (28.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 28th percentile — 28.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000

Affected products

Synology Router Manager — versions 1.3.1-9346
Synology Router Manager (Srm) — versions 1.3, 0

Weakness classification (CWE)

CWE-22 — Path Traversal

References

www.synology.com/en-global/security/advisory/Synology_SA_25_04 (vendor-advisory, Vendor Advisory)

Frequently asked questions

What is CVE-2025-29843?: CVE-2025-29843 is a medium-severity vulnerability in Synology Router Manager, classified under Path Traversal. CVSS score: 5.4/10. Published 2025-12-04.
How severe is CVE-2025-29843?: Medium severity. CVSS v3 base score is 5.4 out of 10.