CVE-2026-31848 HIGH

CVE-2026-31848: Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+

Vendor Nexxt Solutions
Product Nebula 300+
Weakness CWE-312 · Cleartext storage
Published March 23, 2026
Last update March 26, 2026

CVSS base score

8.7/10
Attack vector Adjacent
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

March 23, 2026 CVE published
March 26, 2026 Record updated