How severe is CVE-2021-40122?

CVE-2021-40122 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2021-40122 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-40122?

CVE-2021-40122 affects Cisco Meeting Server. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-40122?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-40122 published?

CVE-2021-40122 was published on 2021-10-21 and last updated on 2026-06-17.

CVE-2021-40122

CVE-2021-40122 is a medium-severity vulnerability in Cisco Meeting Server with a CVSS 3.x base score of 5.9. 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-404.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v2: 5.0
EPSS exploit prediction: 1% (62nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-404
Affected product: Cisco Meeting Server
Published: 2021-10-21
Last modified: 2026-06-17

Description

A vulnerability in an API of the Call Bridge feature of Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper handling of large series of message requests. An attacker could exploit this vulnerability by sending a series of messages to the vulnerable API. A successful exploit could allow the attacker to cause the affected device to reload, dropping all ongoing calls and resulting in a DoS condition.

Frequently asked questions

What is CVE-2021-40122?: A vulnerability in an API of the Call Bridge feature of Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper handling of large series of message requests. An attacker could exploit this vulnerability by sending a series of messages to the vulnerable API. A successful exploit could allow the attacker to cause the affected device to reload, dropping all ongoing calls and resulting in a DoS condition.
How severe is CVE-2021-40122?: CVE-2021-40122 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2021-40122 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (62nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-40122?: CVE-2021-40122 affects Cisco Meeting Server. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-40122?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-40122 published?: CVE-2021-40122 was published on 2021-10-21 and last updated on 2026-06-17.

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cms-LAHe8z5v

Affected products (1)

cpe:2.3:a:cisco:meeting_server:*:*:*:*:*:*:*:*

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-2016-6445 — Critical (CVSS 9.1): A vulnerability in the Extensible Messaging and Presence Protocol (XMPP) service of the Cisco Meeting Server (CMS)…
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…

All CVEs affecting Cisco Meeting Server →

Other CWE-404 vulnerabilities

CVE-2023-24444 — Critical (CVSS 9.8): Jenkins OpenID Plugin 2.4 and earlier does not invalidate the previous session on login.
CVE-2024-31611 — Critical (CVSS 9.1): SeaCMS 12.9 has a file deletion vulnerability via admin_template.php.
CVE-2018-8450 — High (CVSS 8.8): A remote code execution vulnerability exists when Windows Search handles objects in memory, aka "Windows Search Remote…
CVE-2026-11317 — High (CVSS 8.7): A denial of service security issue exists in the affected product. The security issue stems from a fault occurring when…
CVE-2022-25762 — High (CVSS 8.6): If a web application sends a WebSocket message concurrently with the WebSocket connection closing when running on…
CVE-2020-26070 — High (CVSS 8.6): A vulnerability in the ingress packet processing function of Cisco IOS XR Software for Cisco ASR 9000 Series…

Browse all CWE-404 vulnerabilities →