Exploited

CVE-2022-26143

Mitel MiCollab · Collaboration, telephony and video conferencing

MiCollab, MiVoice Business Express Access Control Vulnerability

At a glance

Exploited. Added to CISA’s catalog of exploited vulnerabilities on March 25, 2022.

Affected product: Mitel MiCollab (category Collaboration, telephony and video conferencing, indicative classification). Name in CISA’s catalog: Mitel MiCollab, MiVoice Business Express.

What should I do?

Apply the security update from Mitel.

Deadline set by CISA for US federal agencies: 21 days (due April 15, 2022). It only binds those agencies, but it is a useful measure of urgency.

Mitel security advisories page (general page, not the advisory for this vulnerability)
The vendor’s specific advisory is listed in the NVD references: CVE-2022-26143 on the NVD website.

Original text of the required action (CISA)

Apply updates per vendor instructions.

Timeline

March 10, 2022 Vulnerability published Publication date (NVD)
March 25, 2022 Exploitation confirmed Added to CISA’s KEV catalog
April 15, 2022 CISA deadline Remediation deadline set for US federal agencies

The facts, with their sources

Exploitation confirmed: Yes, on March 25, 2022 Date added to the catalog of exploited vulnerabilities. Exploitation itself may have started earlier. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Ransomware: No known use to date That does not guarantee it is not being used: the information is not public. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Hunt for compromise: Not requested by CISA Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA required action: Apply the security update from Mitel. Rewritten by this site from CISA’s original text. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CISA deadline: April 15, 2022, 21 days Set for US federal agencies: a measure of urgency, not an obligation elsewhere. Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
Vulnerability published: March 10, 2022 Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC
Product according to CISA: Mitel MiCollab, MiVoice Business Express Filed by this site under “Collaboration, telephony and video conferencing” (indicative classification). Source: KEV catalog, collected September 29, 2026 at 14:57 UTC
CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Technical detail of the score: attack vector, complexity, impact. Source: National Vulnerability Database (NVD), collected September 29, 2026 at 15:00 UTC

Severity and activity

9.8 / 10 CVSS severity: critical

Score from the NVD. Collected Sep 29, 2026.

— Probability of exploitation in the next 30 days (EPSS)

FIRST’s EPSS model. Since exploitation is already confirmed, this figure is mostly useful to compare activity. Collected Sep 29, 2026.

Description

The TP-240 (aka tp240dvr) component in Mitel MiCollab before 9.4 SP1 FP1 and MiVoice Business Express through 8.1 allows remote attackers to obtain sensitive information and cause a denial of service (performance degradation and excessive outbound traffic). This was exploited in the wild in February and March 2022 for the TP240PhoneHome DDoS attack.

A vulnerability has been identified in MiCollab and MiVoice Business Express that may allow a malicious actor to gain unauthorized access to sensitive information and services, cause performance degradations or a denial of service condition on the affected system.

Summary from CISA (KEV catalog).

CERT-FR advisories

No advisory among the latest CERT-FR publications this site follows. That does not mean there are none.

Information reused under the Open Licence 2.0 (Etalab); the date of last update is shown for each advisory. This site is neither affiliated with nor endorsed by ANSSI.

Sources for this page

CISA KEV catalog: exploitation, date added, required action, deadline, ransomware.
NVD (NIST): CVSS severity, publication date, description, vendor references.
EPSS (FIRST): probability of exploitation.
CERT-FR: advisories and alerts (in French).
Brand and category: indicative classification by this site (method).