# CVE-2025-29896: QNAP Qsync Central NULL pointer dereference

Source: https://junglewise.ai/threats/cve-2025-29896-a-null-pointer-dereference-vulnerability-has-been-reported-to  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-15. Updated: 2026-10-19  
License: CC BY 4.0 with a link back

CVE-2025-29896 · Severity: info · Published 2026-10-15

Qsync Central is a file synchronization service for QNAP NAS devices. A NULL pointer dereference vulnerability allows an authenticated remote attacker to crash the service, causing a denial of service. The vulnerability requires the attacker to already have a valid user account on the system.

Technologies: [QNAP Qsync Central](https://junglewise.ai/threats/technologies/qsync-central). Vendors: [QNAP](https://junglewise.ai/threats/vendors/qnap).

## Quick answers

**Is CVE-2025-29896 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2025-29896 being exploited in the wild.

**How severe is CVE-2025-29896?** Informational severity, published 15 October 2026.

**Which products and versions are affected?** QNAP Qsync Central before 5.0.0.4.

**Is there a fix for CVE-2025-29896?** Yes: fixed in Qsync Central 5.0.0.4 and later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2025-29896 attacked?** It is attacked over the network, in a network appliance.

**Am I affected by CVE-2025-29896?** Check whether you run QNAP Qsync Central at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- Fixed in Qsync Central 5.0.0.4 and later

## Technical details

A NULL pointer dereference in Qsync Central allows an authenticated remote attacker to trigger a denial-of-service condition by causing the application to crash. The vulnerability requires prior authentication with a valid user account. The attack vector is network-based and does not require elevated privileges or additional user interaction beyond account access.

## Affected products

- QNAP Qsync Central before 5.0.0.4

## Timeline

- 2026-10-15: disclosed

## References

- [https://www.qnap.com/en/app-release-notes?keyword=Qsync%20&app=QsyncServer&product-line=nas](https://www.qnap.com/en/app-release-notes?keyword=Qsync%20&app=QsyncServer&product-line=nas)

## Related threats

- [QNAP Qsync Central buffer overflow](https://junglewise.ai/threats/cve-2025-29897-a-buffer-copy-without-checking-size-of-input-vulnerability-has)
- [QNAP Qsync Central NULL pointer dereference](https://junglewise.ai/threats/cve-2025-29895-a-null-pointer-dereference-vulnerability-has-been-reported-to)
- [A path traversal vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account…](https://junglewise.ai/threats/cve-2025-57712-a-path-traversal-vulnerability-has-been-reported-to-affect-qsync)