SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

CVE-2026-31848

Because the encoding is reversible and lacks integrity protection, an attacker can reconstruct or forge a valid cookie value without proper authentication.

HIGH 8.7EPSS 0.28%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.28%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 uses the ecos_pw cookie for authentication, which contains Base64-encoded credential data combined with a static suffix. Because the encoding is reversible and lacks integrity protection, an attacker can reconstruct or forge a valid cookie value without proper authentication.

CVSS 4.0
8.7 HIGHCVSS:4.0/AV:A/AC:L/AT:N/PR:N/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
0.28% probability · 21th percentile
CISA KEV
Not listed
Weakness
CWE-312
Affected
nexxtsolutions/nebula300plus firmware
Source
309f9ea4-e3e9-4c6c-b79d-e8eb01244f2c

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