CVE-2025-62839: QNAP Systems HBS 3 Hybrid Backup Sync · Use of Hard-coded Cryptographic Key
Affects QNAP Systems HBS 3 Hybrid Backup SyncSource CVE Database V5
Not known to be exploited · CVSS 8.7 High : upgrade to 26.4.0.521 soon.
Data as of 29 Oct 2026, 08:11 UTC
Thin evidence
One scorer or none| CNA (qnap) | CVSS 4.0 | 8.7 |
|---|
- Patch
- Available – fixed in 26.4.0.521, 26.4.1.563
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:NExploitation evidence
Disclosed: evidence found.
CVE published 29 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: 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 29 Oct 2026.
What to do
Upgrade HBS 3 Hybrid Backup Sync to 26.4.0.521; Hybrid Backup Sync to 26.4.1.563 or 26.4.0.521.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| QNAP Systems Inc.HBS 3 Hybrid Backup Sync | Affected
| Fixed in
|
| QNAP Systems Inc.Hybrid Backup Sync | Affected
| Fixed in
|
| QNAP Systems Inc.Hybrid Backup Sync | Affected
| Fixed in
|
AI-suggested
Apply the official fixes by upgrading to HBS 3 Hybrid Backup Sync version 26.4.0.521 or later, and Hybrid Backup Sync version 26.4.1.563 or later. These versions contain the remediation for the hard-coded cryptographic key vulnerability.
Description
CVE-2025-62839 is a high-severity vulnerability in QNAP Systems Inc.'s HBS 3 Hybrid Backup Sync and Hybrid Backup Sync products caused by the use of a hard-coded cryptographic key. This flaw could allow remote attackers to compromise system security. The issue has been fixed in versions 26.4.0.521 and later for HBS 3 Hybrid Backup Sync, and 26.4.1.563 and later for Hybrid Backup Sync.