CVE-2026-31848

Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+

Published Mar 23, 2026 CVSS 4.0 · 8.7 High EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
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. This allows unauthorized administrative access to protected endpoints. 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.
Title Nexxt Nebula 300+ - Reversible ecos_pw Cookie Allows Authentication Bypass Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+
Type Values Removed Values Added
Title Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+ Nexxt Nebula 300+ - Reversible ecos_pw Cookie Allows Authentication Bypass
Type Values Removed Values Added
First Time appeared Nexxtsolutions nebula300plus
Nexxtsolutions nebula300plus Firmware
CPEs cpe:2.3:h:nexxtsolutions:nebula300plus:-:*:*:*:*:*:*:*
cpe:2.3:o:nexxtsolutions:nebula300plus_firmware:*:*:*:*:*:*:*:*
Vendors & Products Nexxtsolutions nebula300plus
Nexxtsolutions nebula300plus Firmware
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Type Values Removed Values Added
Description Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 stores administrative authentication material in the ecos_pw cookie using a reversible Base64-encoded format with a static suffix. An attacker who obtains or derives this cookie value can forge a valid administrative session and gain unauthorized access to the device. 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.
Title Reversible ecos_pw cookie allows administrative authentication in Nexxt Nebula 300+ Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+
Type Values Removed Values Added
First Time appeared Nexxtsolutions
Nexxtsolutions nebula300+
Vendors & Products Nexxtsolutions
Nexxtsolutions nebula300+
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 stores administrative authentication material in the ecos_pw cookie using a reversible Base64-encoded format with a static suffix. An attacker who obtains or derives this cookie value can forge a valid administrative session and gain unauthorized access to the device.
Title Reversible ecos_pw cookie allows administrative authentication in Nexxt Nebula 300+
Weaknesses CWE-312
References
Metrics cvssV4_0

{'score': 8.7, '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'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
TuranSec
Published
Updated
Aug 10, 2026, 11:43 AM
Reserved
Mar 9, 2026, 6:20 PM
Status
Modified
Published
Mar 23, 2026, 1:16 PM
Modified
Aug 10, 2026, 12:17 PM