Besen BS20 EV Charging Station BLE/WiFi authentication replay

published 2026-05-24 5mo ago modified 2026-07-23 3mo ago also EUVD-2026-31550

cvss: 3.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.3%; EPSS 0.3% chance of exploitation in 30 days, percentile 22%
public exploits: 0; none known

A security vulnerability has been detected in Besen BS20 EV Charging Station up to 20260426. This affects an unknown part of the component BLE/WiFi. Such manipulation leads to authentication bypass by capture-replay. The attack must be carried out from within the local network. Attacks of this nature are highly complex. It is indicated that the exploitability is difficult. The original disclosure mentions, that "[t]hese vulnerabilities have been reported to Besen and we have received their acknowlegement that they are reviewing this as of April 2026."

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CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 5mo ago (2026-05-29)

Exploit prediction

0.29% chance of exploitation in the next 30 days, higher than 22% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by	version	score	vector
CNA	4.0	2.3	CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
CNA	3.1	3.1	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R
CNA	3.0	3.1	CVSS:3.0/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N/E:P/RL:X/RC:R
CNA	2.0	1.8	AV:A/AC:H/Au:N/C:N/I:P/A:N/E:POC/RL:ND/RC:UR
CNA	4.0	1.3	CVSS:4.0/AV:A/AC:H/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CNA	3.1	3.1	CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CNA	2.0	1.8	AV:A/AC:H/Au:N/C:N/I:P/A:N

Affected products

Besen BS20 EV Charging Station

Classification

Weakness

CWE-294 Authentication Bypass by Capture-replay
CWE-287 Improper Authentication

References

vuldb.com /vuln/365379
vdb-entry
vuldb.com /vuln/365379/cti
signature, permissions-required
vuldb.com /submit/813577
third-party-advisory
github.com /carfeii/besen#finding-5-unauthorized-tampering-of-charger-commands
related

Sources

CVE List CVE-2026-9398
NVD CVE-2026-9398

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