CVE-2022-26143

Exp

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.

Published: 2022-03-10 Last update: 2025-11-03 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-26143 is rated Critical Active Threat (98.7/100): CVSS Critical severity, with high exploitation likelihood (EPSS 89.15%, 100th percentile). CISA KEV confirms active exploitation (added 2022-03-25) affecting Mitel / MiCollab, MiVoice Business Express. a weakness (CWE-306) Unauthenticated remote administrative access may be possible. The CISA remediation deadline has passed—treat as an emergency patch priority.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

CISA KEV Record for CVE-2022-26143

Name: MiCollab, MiVoice Business Express Access Control Vulnerability · CISA KEV detail

Exploit added: 2022-03-25

Action due: 2022-04-15

Required action: Apply updates per vendor instructions.

Public exploit references (Exploit-DB) for CVE-2022-26143

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2022-26143

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 2026-04-16 89.51% 89.15% -0.36%
2 2026-03-26 89.20% 89.51% +0.31%
3 2025-11-21 — 89.20% —

Full EPSS history (29 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-26143

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 [email protected]
9.8 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 5.9 134c704f-9b21-4f2e-91b3-4a467353bcc0
9.0 2.0 HIGH
AV:N/AC:L/Au:N/C:P/I:P/A:C Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:C)
Complete availability impact.
 10.0 8.5 [email protected]

Weakness enumeration for CVE-2022-26143

Affected software / configurations for CVE-2022-26143

Vendor Product Version Raw CPE
mitel micollab < 9.4 cpe:2.3:a:mitel:micollab:*:*:*:*:*:-:*:*
mitel micollab 9.4 cpe:2.3:a:mitel:micollab:9.4:-:*:*:*:-:*:*
mitel micollab 9.4 cpe:2.3:a:mitel:micollab:9.4:sp1:*:*:*:-:*:*
mitel mivoice_business_express <= 8.1 cpe:2.3:a:mitel:mivoice_business_express:*:*:*:*:*:*:*:*

References for CVE-2022-26143

URL Tags
https://arstechnica.com/information-technology/2022/03/ddosers-use-new-method-capable-of-amplifying-traffic-by-a-factor-of-4-billion/ Exploit Press/Media Coverage Third Party Advisory
https://blog.cloudflare.com/cve-2022-26143/ Mitigation Third Party Advisory
https://news.ycombinator.com/item?id=30614073 Issue Tracking Third Party Advisory
https://team-cymru.com/blog/2022/03/08/record-breaking-ddos-potential-discovered-cve-2022-26143/ Broken Link Mitigation Third Party Advisory
https://www.akamai.com/blog/security/phone-home-ddos-attack-vector Mitigation Third Party Advisory
https://www.mitel.com/en-ca/support/security-advisories/mitel-product-security-advisory-22-0001 Vendor Advisory
https://www.shadowserver.org/news/cve-2022-26143-tp240phonehome-reflection-amplification-ddos-attack-vector/ Mitigation Third Party Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2022-26143 US Government Resource
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