Cross-site scripting (XSS) vulnerability in the file browser in Guacamole 0.9.8 and 0.9.9, when file transfer is enabled to a location shared by multiple users, allows remote authenticated users to inject arbitrary web script or HTML via a crafted filename. NOTE: this vulnerability was fixed in guacamole.war on 2016-01-13, but the version number was not changed.
Conclusion & alert: CVE-2016-1566 is rated Moderate Risk (51.7/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 2.22%). Core evidence: EPSS rose +2.03% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).
| # | Date | Old EPSS score | New EPSS score | Delta (New - Old) |
|---|---|---|---|---|
| 1 | 2026-06-15 | 0.18% | 2.22% | +2.03% |
| 2 | 2025-03-30 | 0.36% | 0.18% | -0.18% |
| 3 | 2025-03-29 | — | 0.36% | — |
Full EPSS history (6 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 5.4 | 3.0 | MEDIUM |
|
2.3 | 2.7 | [email protected] |
| 3.5 | 2.0 | LOW |
|
6.8 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
ubuntu
|
medium | CVE-2016-1566 medium priority: Ubuntu including 2 source packages (guacamole-client, guacamole-server), 18 status rows across 9 suites (artful, bionic, cosmic, precise, trusty, upstream, xenial, yakkety, zesty): ignored 6, not-affected 6, DNE 4, needed 2. | https://ubuntu.com/security/CVE-2016-1566 |
| URL | Tags |
|---|---|
| https://sourceforge.net/p/guacamole/news/2016/02/security-advisory---stored-xss-cve-2016-1566--guac-1465/ | Third Party Advisory |