Arbitrary file upload in Bytedesk
CVE-2026-3748
A security flaw has been discovered in Bytedesk up to 1.3.9. This affects the function uploadFile of the file source-code/src/main/java/com/bytedesk/core/upload/UploadRestController.java of the component SVG File Handler. Performing a manipulation results in unrestricted upload. Remote exploitation of the attack is possible. The exploit has been released to the public and may be used for attacks. Upgrading to version 1.4.5.1 is able to mitigate this issue. The patch is named 975e39e4dd527596987559f56c5f9f973f64eff7. Upgrading the affected component is recommended.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
EPSS: 0.007 (49.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 50th percentile — 49.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.005 · newest: 0.007 · change: +0.002
Affected products
- Bytedesk
- Bytedesk — versions 1.3.0, 1.3.1, 1.3.2
Weakness classification (CWE)
References
- vuldb.com/ (technical-description, VDB Entry, Third Party Advisory, vdb-entry)
- vuldb.com/ (signature, Permissions Required, permissions-required)
- vuldb.com/ (VDB Entry, Third Party Advisory, third-party-advisory)
- github.com/Bytedesk/bytedesk/issues/18 (issue-tracking, Exploit, Issue Tracking, Vendor Advisory)
- github.com/Bytedesk/bytedesk/issues/18 (issue-tracking, Exploit, Issue Tracking, Vendor Advisory)
- github.com/Bytedesk/bytedesk/issues/18 (issue-tracking, Exploit, exploit, Issue Tracking, Vendor Advisory)
- github.com/Bytedesk/bytedesk/commit/975e39e4dd527596987559f56c5f9f973f64eff7 (Patch, patch)
- github.com/Bytedesk/bytedesk/releases/tag/v1.4.5.1 (Release Notes, patch)
- github.com/Bytedesk/bytedesk/ (Product, product)
Frequently asked questions
- What is CVE-2026-3748?
- CVE-2026-3748 is a medium-severity vulnerability in Bytedesk, classified under Improper Access Control. CVSS score: 6.3/10. Published 2026-03-08.
- How severe is CVE-2026-3748?
- Medium severity. CVSS v3 base score is 6.3 out of 10.