PatchTheCVECVE-2026-39991: A cross-site scripting (XSS) vulnerability has been reported to affect Notes Station 3
CVE-2026-39991 is a medium-severity flaw (CVSS 4.8) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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
Why this priority
- No elevated risk signals yet
No fix is published yet: follow the downgrade or mitigation steps.
Risk facts
| CVSS score | 4.8 (Medium) |
| Attack vector | Network (remote) |
| Attack complexity | Low |
| Privileges needed | Low |
| User interaction | Active |
| EPSS exploit chance | 0.3% (top 78%) |
| CISA exploited list | No |
| Weakness | CWE-79 |
| Published | 2026-10-15 |
| Last modified | 2026-10-15 |
Last updated 2026-10-15 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-39991?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-39991 being exploited?
CVE-2026-39991 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-39991 affect?
CVE-2026-39991 affects affected software. Severity is medium (CVSS 4.8). 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
How urgent is CVE-2026-39991?
Priority 22/100. No elevated risk signals yet.