Secuno
ENNL
Book demo

CVE-2025-66738

Yealink Sip-t21(p)e2 Firmware remote code execution

8.8 HIGHPublic exploitEPSS 0.63%
  1. Published26 Dec 2025

Description

An issue in Yealink T21P_E2 Phone 52.84.0.15 allows a remote normal privileged attacker to execute arbitrary code via a crafted request the ping function of the diagnostic component.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredLow
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Yealink Sip-t21(p)e2 Firmware52.84.0.15

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-10911010.0
A flaw has been found in Wavlink WL-WN592AX6 250422. This issue affects the function…
CVE-2026-1091089.9
A security vulnerability has been detected in Wavlink WL-WN530BE1-A 251117. This…
CVE-2026-10891810.0
A vulnerability was identified in Edimax BR-6208AC 1.32. Impacted is an unknown…
CVE-2026-10891710.0
A vulnerability was determined in Edimax BR-6208AC 1.32. This issue affects some…
CVE-2026-1089168.3
A vulnerability was found in Edimax BR-6208AC 1.32. This vulnerability affects unknown…
CVE-2026-1088969.9
A vulnerability was found in Linksys E1700 1.0.0.4.003. This affects the function…

Frequently asked

Is CVE-2025-66738 being actively exploited?

CVE-2025-66738 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.63%.

How severe is CVE-2025-66738?

CVE-2025-66738 has a CVSS 3.1 base score of 8.8, rated high. EPSS estimates a 0.63% probability of exploitation.

Which products are affected by CVE-2025-66738?

Affected products include Yealink Sip-t21(p)e2 Firmware.

How do I fix CVE-2025-66738?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2025-66738 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.