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  4. CVE 2026 39991 stored cross site scripting xss in note station
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Back to active CVEs
Medium · CVSS 4.8CVE-2026-39991

Stored Cross-Site Scripting (XSS) in Note Station file upload functionalityCVE-2026-39991

Answer in brief

CVE-2026-39991 records a Medium severity (CVSS 4.8) vulnerability in Stored Cross-Site Scripting (XSS) in Note Station file upload functionality. The current sources do not mark it as known exploited. The current feed maps QNAP Systems Inc./Notes Station 3 (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 15, 2026Updated Oct 15, 2026Source checked Oct 15, 2026First seen by HOL Oct 15, 2026Material review Oct 15, 2026
Upstream Advisory

Key facts

Risk
Medium · CVSS 4.8
Exploitation
Not marked as known exploited
Affected software
1 mapped package or product
Fix availability
Available

Why this deserves its current priority

CVSS is 4.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps QNAP Systems Inc./Notes Station 3 (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
PackageAffected rangeFixed version
QNAP Systems Inc./Notes Station 3generic>=3.9.x <3.9.123.9.12

Recommended response

  1. 1Check inventory. Check lockfiles and deployed manifests for QNAP Systems Inc./Notes Station 3.
  2. 2Review the reported fix. Source-reported solution: We have already fixed the vulnerability in the following version: Notes Station 3 3.9.12 and later

Evidence timeline and material changes

  1. Published upstream

    Oct 15, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  2. Source modified

    Oct 15, 2026

    Evidence: source:cvelist:source_dates:source-dates:record

  3. First seen by HOL

    Oct 15, 2026

Sources and claim methodology

  • Source referenceqnap.com
Upstream source description

A cross-site scripting (XSS) vulnerability has been reported to affect Notes Station 3. If a remote attacker gains a user account, they can then exploit the vulnerability to inject malicious code. We have already fixed the vulnerability in the following version: Notes Station 3 3.9.12 and later

Quoted source text, attributed separately from HOL analysis.

Related CVEs

  • **RCE** Unsanitized `X-Forwarded-For` header passed to `shell_exec()` via broken IP validation fallback in `getClientIP()`Same qnap systems inc./notes station 3 package
  • **Privilege Escalation** World-writable crontab path monitored and executed by root-owned processSame qnap systems inc./notes station 3 package
  • **Container Escape** Host user home directory mounted with write access into application containerSame qnap systems inc./notes station 3 package
  • Privilege Escalation via QuFTP Log-based XSSAlso CWE-79
  • Steve doesn’t verify a server’s certificate and is susceptible to man-in-the-middle (MitM) attacksSame generic ecosystem
  • Rancher users who can create Projects can gain access to arbitrary projectsSame generic ecosystem

Record context

Vulnerability class
XSS
EPSS
Not reported
CWE IDs
CWE-79
Source
CVE List V5
Source checked
Oct 15, 2026
References
1 linked source
Open source record