SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-23759

Perle IOLAN STS/SCS terminal server models with firmware versions prior to 6.0 allow authenticated OS command injection via the restricted shell accessed over Telnet or SSH.

HIGH 8.6EPSS 1.51%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (1.51%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Perle IOLAN STS/SCS terminal server models with firmware versions prior to 6.0 allow authenticated OS command injection via the restricted shell accessed over Telnet or SSH. The shell 'ps' command does not perform proper argument sanitization and passes user-supplied parameters into an 'sh -c' invocation running as root. An authenticated attacker who can log in to the device can inject shell metacharacters after the 'ps' subcommand to execute arbitrary OS commands with root privileges, leading to full compromise of the underlying operating system.

CVSS 4.0
8.6 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
1.51% probability · 73th percentile
CISA KEV
Not listed
Weakness
CWE-78
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.