CVE-2025-48721: qnap systems inc. qts Classic Buffer Overflow

Vulnerability summary

CVE-2025-48721 is a medium (CVSS 6.5) Classic Buffer Overflow vulnerability in qnap systems inc. qts. EPSS estimates a 0.43% chance of exploitation in the next 30 days, higher than 35.9% of scored vulnerabilities.

Timeline

1. 02-01-2026
   PublishedVulnerability first disclosed.
2. 02-01-2026
   Last modifiedVulnerability information updated.

Description

A buffer overflow vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to modify memory or crash processes. We have already fixed the vulnerability in the following version: QTS 5.2.8.3332 build 20251128 and later

• CWE-120Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.
• CWE-121Stack-based Buffer OverflowA stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).