Cyber Resilience

CVE-2025-52863

Memory Safety in Qnap Quts Hero h5.2.0.2737 … h5.3.0.3192

Memory Safety
Published
02 January 2026
Modified
05 January 2026
Patch / advisory
View advisory
CVSS Score v4 1.3
Click a component to see what it means
Raw vectorCVSS: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:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0031 24th percentile
Risk Priority 25 floored blend · peak EPSS

Summary

CVE-2025-52863 is a low-severity Classic Buffer Overflow (CWE-120) vulnerability in Qnap Quts Hero. Its CVSS base score is 1.3 (Low).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked at the 24th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SI-10 (Information Input Validation) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2025-52863 is a buffer overflow vulnerability (CWE-120) affecting several versions of QNAP operating systems, including QTS and QuTS hero. Published on 2026-01-02, it carries a CVSS v3.1 base score of 8.1 (AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H), indicating high severity due to its potential for integrity and availability impacts without requiring user interaction.

A remote attacker who has gained a user account on an affected system can exploit the vulnerability over the network with low complexity. Successful exploitation allows the attacker to modify memory or crash processes, enabling denial-of-service conditions or unauthorized data manipulation.

QNAP has fixed the vulnerability in QTS 5.2.7.3256 build 20250913 and later, QuTS hero h5.2.7.3256 build 20250913 and later, and QuTS hero h5.3.0.3192 build 20250716 and later. Additional details are available in the vendor's security advisory at https://www.qnap.com/en/security-advisory/qsa-25-50.

EU & UK References

Vulnerability Data

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…

more

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

CWE(s)
CWE-120

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-45042Same product: Qnap Qts
CVE-2023-45044Same product: Qnap Qts
CVE-2023-45043Same product: Qnap Qts
CVE-2023-32968Same product: Qnap Qts
CVE-2023-32975Same product: Qnap Qts
CVE-2023-45041Same product: Qnap Qts
CVE-2025-52872Same product: Qnap Qts
CVE-2025-52864Same product: Qnap Qts
CVE-2023-45040Same product: Qnap Qts
CVE-2023-45039Same product: Qnap Qts

Affected Assets

qnap
quts hero
h5.2.0.2737, h5.2.0.2782, h5.2.0.2789, h5.2.0.2802, h5.2.0.2823
qnap
qts
5.2.0.2737, 5.2.0.2744, 5.2.0.2782, 5.2.0.2802, 5.2.0.2823

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V5.2.1

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and analysis can find missing size checks before deployment.

SI-10 Information Input Validation good match

Input validation directly enforces size checks before buffer copies.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles require bounds checking and safe buffer handling in design.

SI-16 Memory Protection partial match

Memory protection limits the impact of an overflow once it occurs.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure development practices directly enforce bounds checking and input validation that prevent classic buffer overflows.

ID.RA-01 partial match
prevents

Vulnerability identification processes such as code review or scanning detect classic buffer overflows before exploitation.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing unchecked buffer copies with corrected versions.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

A.8.28 Secure coding mostly match
prevents

Secure coding directly requires bounds-checked memory operations, addressing the root cause of CWE-120.

A.8.29 Security testing in development and acceptance mostly match
finds

Security testing in development and acceptance can detect buffer overflows through fuzzing and static analysis, though it does not prevent them at the source.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates processes that can include input validation and bounds checking to prevent buffer overflows.

A.8.26 Application security requirements partial match
prevents

Application security requirements can specify input-size validation and safe buffer handling to mitigate classic buffer overflows.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure system architecture and engineering principles promote defensive coding patterns that reduce the likelihood of unchecked buffer copies.

References