CVE-2026-21638

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: UBB-XG (Version 1.2.2 and earlier) UDB-Pro/UDB-Pro-Sector (Version 1.4.1 and earlier) UBB (Version 3.1.5 and earlier) Mitigation: Update your UBB-XG to Version 1.2.3 or later. Update your UDB-Pro/UDB-Pro-Sector to Version 1.4.2 or later. Update your UBB to Version 3.1.7 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-2026-21638 is rated Moderate Risk (43.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.09%). Review affected assets and schedule remediation.

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-2026-21638

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 2026-06-06 0.20% 0.09% -0.11%
2 2026-02-09 0.08% 0.20% +0.12%
3 2026-01-09 — 0.08% —

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-21638

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
8.8 3.1 HIGH
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H 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: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.
 2.8 5.9 [email protected]

Weakness enumeration for CVE-2026-21638

Affected software / configurations for CVE-2026-21638

Vendor Product Version Raw CPE
ui ubb-xg_firmware < 1.2.3 cpe:2.3:o:ui:ubb-xg_firmware:*:*:*:*:*:*:*:*
ui udb-pro_firmware < 1.4.2 cpe:2.3:o:ui:udb-pro_firmware:*:*:*:*:*:*:*:*
ui udb-pro-sector_firmware < 1.4.2 cpe:2.3:o:ui:udb-pro-sector_firmware:*:*:*:*:*:*:*:*
ui ubb_firmware < 3.1.7 cpe:2.3:o:ui:ubb_firmware:*:*:*:*:*:*:*:*

References for CVE-2026-21638

cvelogic Threat Intelligence