CVE-2026-21639

A malicious actor in Wi-Fi range of the affected product could leverage a vulnerability in the airMAX Wireless Protocol to achieve a remote code execution (RCE) within the affected product. Affected Products: airMAX AC (Version 8.7.20 and earlier) airMAX M (Version 6.3.22 and earlier) airFiber AF60-XG (Version 1.2.2 and earlier) airFiber AF60 (Version 2.6.7 and earlier) Mitigation: Update your airMAX AC to Version 8.7.21 or later. Update your airMAX M to Version 6.3.24 or later. Update your airFiber AF60-XG to Version 1.2.3 or later. Update your airFiber AF60 to Version 2.6.8 or later.

Published: 2026-01-08 Last update: 2026-01-14 Assigner: [email protected] Source: [email protected]
NVD Status：Analyzed，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2026-21639 is rated Low Risk (28.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.27%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

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

Exploit prediction scoring system (EPSS) score for CVE-2026-21639

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 2026-06-15 0.03% 0.27% +0.24%
2 2026-06-06 0.07% 0.03% -0.04%
3 2026-02-09 — 0.07% —

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-21639

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.4 3.1 MEDIUM
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N Click to expand
Attack vector (AV:A)
Attacker has to be nearby on the network—same office, same link, that vibe—not the whole wide internet.
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:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:L)
Attackers could change some data, but it’s limited—not everything goes.
Availability (A:N)
Service keeps running; no real outage angle.
 2.8 2.5 134c704f-9b21-4f2e-91b3-4a467353bcc0

Weakness enumeration for CVE-2026-21639

Affected software / configurations for CVE-2026-21639

Vendor Product Version Raw CPE
ui airmax_ac_firmware < 8.7.21 cpe:2.3:o:ui:airmax_ac_firmware:*:*:*:*:*:*:*:*
ui airmax_m_firmware < 6.3.24 cpe:2.3:o:ui:airmax_m_firmware:*:*:*:*:*:*:*:*
ui airfiber_af60-xg_firmware < 1.2.3 cpe:2.3:o:ui:airfiber_af60-xg_firmware:*:*:*:*:*:*:*:*
ui airfiber_af60_firmware < 2.6.8 cpe:2.3:o:ui:airfiber_af60_firmware:*:*:*:*:*:*:*:*

References for CVE-2026-21639

cvelogic Threat Intelligence