CVE-2026-31848: Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 uses the ecos_pw cookie for authentication, which contains Base64-encoded credential data…

PriorityP265critical9.8CVSS 3.1

AVNACLPRNUINSUCHIHAH

EPSS

0.28%

19.8th percentile

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. This allows unauthorized administrative access to protected endpoints.

Affected

2 ranges

Vendor	Product	Version range	Fixed in
nexxt_solutions	nebula_300	<= 12.01.01.37	—
nexxtsolutions	nebula300plus_firmware	<= 12.01.01.37	—

CVSS provenance

nvdv3.19.8CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvdv4.08.7HIGHCVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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