TLS cipher suites with CBC mode in TLS 1.1 and 1.2 in MatrixSSL before 3.8.3 allow remote attackers to cause a denial of service (out-of-bounds read) via a crafted message.
Conclusion & alert: CVE-2016-6884 is rated Moderate Risk (50.4/100): CVSS Medium severity, with medium exploitation likelihood (EPSS 1.33%). 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 | 0.48% | 1.33% | +0.85% |
| 2 | 2025-03-30 | 0.39% | 0.48% | +0.09% |
| 3 | 2025-03-29 | — | 0.39% | — |
Full EPSS history (7 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 6.5 | 3.0 | MEDIUM |
|
2.8 | 3.6 | [email protected] |
| 4.3 | 2.0 | MEDIUM |
|
8.6 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
ubuntu
|
medium | CVE-2016-6884 medium priority: Ubuntu including 1 source packages (matrixssl), 10 status rows across 10 suites (artful, bionic, cosmic, disco, precise, trusty, upstream, xenial, yakkety, zesty): DNE 8, ignored 1, released 1. | https://ubuntu.com/security/CVE-2016-6884 |
| URL | Tags |
|---|---|
| http://www.openwall.com/lists/oss-security/2016/08/19/8 | Mailing List Third Party Advisory |
| http://www.securityfocus.com/bid/91488 | |
| https://github.com/matrixssl/matrixssl/blob/master/CHANGES.md | Release Notes Vendor Advisory |