synced 12 MIN AGO
01 Record

CVE-2026-39991

Stored Cross-Site Scripting (XSS) in Note Station file upload functionality

MediumPUBLISHEDCNA: qnap
CNA base score4.8 CVSS v4.0CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

02 Description

Stored Cross-Site Scripting (XSS) in Note Station file upload functionality

03 Exploitation and scoring

Exploitation
Assessed, none found. CISA's assessment recorded neither public exploit code nor evidence of exploitation when it was made.
SSVC decision
  • ExploitationnoneCISA recorded no public exploit code and no evidence of exploitation.
  • AutomatablenoAt least one step from reconnaissance to exploitation cannot be reliably automated.
  • Technical ImpactpartialSuccessful exploitation gives limited control of the vulnerable component.
CISA publishes the decision points, not a final SSVC decision. The decision also depends on mission and well-being impact, which is a property of your deployment rather than of the vulnerability.
EPSS probability
0.29% probability of exploitation activity in the next 30 days.
EPSS percentile
Equal to or higher than the score of 21.6% of scored records. A rank, not a probability.
NVD base score
4.8 (CVSS v4.0), scored by the NVD independently of the CNA.
NVD CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:X/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
NVD analysis status
Awaiting Analysis. NVD last modified this record on 2026-10-15.
Red Hat severity
No Red Hat rating. Red Hat rates the CVEs that affect its products.

Exploit-prediction scores from FIRST. Independent scoring and analysis status from the NVD. Vendor severity from Red Hat. Exploitation assessment and catalog membership from CISA.

04 Metadata

Published
2026-10-15 09:37Z14 DAYS AGO
Last updated
2026-10-29 07:41Z5 HR AGO
Reserved
2026-04-08
Assigning CNA
qnap
Record state
PUBLISHED
Severity
Medium (CVSS 4.8)
CNA CVSS vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Weaknesses
  • CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')Base
Data version
5.2
Document digest
20e475a6cefc1fb0d72ea802485d21637d558ca6bb9eb80c72b9bb4182462d65

05 Affected products

VendorProductVersionsPlatforms
QNAP Systems Inc.Notes Station 33.9.x to < 3.9.12—

06 References

07 Remediation

We have already fixed the vulnerability in the following version: Notes Station 3 3.9.12 and later