How severe is CVE-2016-6445?

CVE-2016-6445 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2016-6445 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2016-6445?

CVE-2016-6445 primarily affects Cisco Meeting Server. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2016-6445?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2016-6445 published?

CVE-2016-6445 was published on 2016-10-27 and last updated on 2026-06-17.

CVE-2016-6445

CVE-2016-6445 is a critical-severity vulnerability in Cisco Meeting Server with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 3% (83rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Cisco Meeting Server
Published: 2016-10-27
Last modified: 2026-06-17

Description

A vulnerability in the Extensible Messaging and Presence Protocol (XMPP) service of the Cisco Meeting Server (CMS) before 2.0.6 and Acano Server before 1.8.18 and 1.9.x before 1.9.6 could allow an unauthenticated, remote attacker to masquerade as a legitimate user. This vulnerability is due to the XMPP service incorrectly processing a deprecated authentication scheme. A successful exploit could allow an attacker to access the system as another user.

Frequently asked questions

What is CVE-2016-6445?: A vulnerability in the Extensible Messaging and Presence Protocol (XMPP) service of the Cisco Meeting Server (CMS) before 2.0.6 and Acano Server before 1.8.18 and 1.9.x before 1.9.6 could allow an unauthenticated, remote attacker to masquerade as a legitimate user. This vulnerability is due to the XMPP service incorrectly processing a deprecated authentication scheme. A successful exploit could allow an attacker to access the system as another user.
How severe is CVE-2016-6445?: CVE-2016-6445 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2016-6445 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 3% (83rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2016-6445?: CVE-2016-6445 primarily affects Cisco Meeting Server. In total, 9 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2016-6445?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2016-6445 published?: CVE-2016-6445 was published on 2016-10-27 and last updated on 2026-06-17.

References

Affected products (9)

cpe:2.3:a:cisco:meeting_server:1.8.15:*:*:*:*:*:*:*
cpe:2.3:a:cisco:meeting_server:1.8_base:*:*:*:*:*:*:*
cpe:2.3:a:cisco:meeting_server:1.9.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:meeting_server:1.9.2:*:*:*:*:*:*:*
cpe:2.3:a:cisco:meeting_server:2.0.0:*:*:*:*:*:*:*
cpe:2.3:a:cisco:meeting_server:2.0.1:*:*:*:*:*:*:*
cpe:2.3:a:cisco:meeting_server:2.0.3:*:*:*:*:*:*:*
cpe:2.3:a:cisco:meeting_server:2.0.4:*:*:*:*:*:*:*
cpe:2.3:a:cisco:meeting_server:2.0.5:*:*:*:*:*:*:*

More vulnerabilities in Cisco Meeting Server

CVE-2016-6448 — Critical (CVSS 9.8): A vulnerability in the Session Description Protocol (SDP) parser of Cisco Meeting Server could allow an…
CVE-2016-6447 — Critical (CVSS 9.8): A vulnerability in Cisco Meeting Server and Meeting App could allow an unauthenticated, remote attacker to execute…
CVE-2017-12249 — Critical (CVSS 9.1): A vulnerability in the Traversal Using Relay NAT (TURN) server included with Cisco Meeting Server (CMS) could allow an…
CVE-2018-0439 — High (CVSS 8.8): A vulnerability in the web-based management interface of Cisco Meeting Server could allow an unauthenticated, remote…
CVE-2016-6444 — High (CVSS 8.8): A vulnerability in Cisco Meeting Server could allow an unauthenticated, remote attacker to conduct a cross-site request…
CVE-2018-0262 — High (CVSS 8.1): A vulnerability in Cisco Meeting Server could allow an unauthenticated, remote attacker to gain unauthorized access to…

All CVEs affecting Cisco Meeting Server →

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-48316 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48281 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48277 — Critical (CVSS 10.0): ColdFusion versions 2025.9, 2023.20 and earlier are affected by an Improper Input Validation vulnerability that could…
CVE-2026-48055 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download any video media. In versions 2.4.0 and…
CVE-2026-34910 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi OS…
CVE-2026-33587 — Critical (CVSS 10.0): Lack of user input sanitisation in Open Notebook v1.8.3 allows the application user to execute Python code (and…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →