CVE-2025-52863: QNAP Systems QTS · Buffer Overflow
Affects QNAP Systems QTSSource CVE Database V5
Not known to be exploited · CVSS 1.3 Low : upgrade to 5.2.7.3256 build 20250913 when convenient.
Data as of 26 Oct 2026, 06:26 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 5.2.7.3256 build 20250913, h5.3.0.3192 build 20250716, h5.2.7.3256 build 20250913
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:UExploitation evidence
Disclosed: evidence found.
CVE published 2 Jan 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 2026-10-26.
What to do
Upgrade QTS to 5.2.7.3256 build 20250913; QuTS hero to h5.3.0.3192 build 20250716 or h5.2.7.3256 build 20250913.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc.QTS | Affected
| Fixed in
|
| QNAP Systems Inc.QuTS hero | Affected
| Fixed in
|
AI-suggested
European organizations should immediately verify the QTS version running on their QNAP NAS devices and upgrade to the patched versions: QTS 5.2.7.3256 build 20250913 or later, or the corresponding QuTS hero builds. Network segmentation should be employed to restrict access to NAS management interfaces to trusted users and systems only. Implement strong authentication controls, including multi-factor authentication, to reduce the risk of credential compromise. Regularly audit user accounts and permissions to limit exposure to low-privilege accounts that could be exploited. Monitor NAS device logs for unusual activity indicative of exploitation attempts or memory corruption errors. Employ network intrusion detection systems with signatures for QNAP vulnerabilities if available. Backup critical data regularly and verify backup integrity to mitigate potential data loss from service disruptions. Finally, maintain an incident response plan that includes NAS device compromise scenarios.
Description
A buffer overflow vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains a user account, they can then exploit the vulnerability to modify memory or crash processes. We have already fixed the vulnerability in the following versions: QTS 5.2.7.3256 build 20250913 and later QuTS hero h5.2.7.3256 build 20250913 and later QuTS hero h5.3.0.3192 build 20250716 and later