Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+
Priority LOW 39CWE-312Published · Updated
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Information disclosure
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-312.
Summary
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.
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00295 22nd percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Nexxt Solutions | Nebula 300+ | up to 12.01.01.37 | — | No fix listed | CNA |
- Nebula 300+ VendorNexxt Solutions Affected up to 12.01.01.37 Fixed in — No fix listed CNA
CPE configurations NVD · 2
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:nexxtsolutions:nebula300plus_firmware:*:*:*:*:*:*:*:* | up to 12.01.01.37 | Vulnerable | Nexxt Solutions |
| cpe:2.3:h:nexxtsolutions:nebula300plus:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Nexxt Solutions |
- cpe:2.3:o:nexxtsolutions:nebula300plus_firmware:*:*:*:*:*:*:*:* Versions up to 12.01.01.37 Vulnerable ·Nexxt Solutions
- cpe:2.3:h:nexxtsolutions:nebula300plus:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Nexxt Solutions
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-31848
- 2026-10-03 Alias added: GHSA-7xw4-69gx-5gch
- 2026-10-25 Priority changed: MEDIUM → LOW
References
Advisory 2
More Nexxt Solutions Nebula300plus Firmware vulnerabilities
- TI-2026-24400 Hidden Functionality Enables Remote Telnet Activation via /goform/setSysTools in Nexxt Nebula 300+ CVSS 4.0HIGH 8.5
- TI-2026-24404 Nexxt Nebula 300+ - Lack of Rate Limiting Enables Brute-Force Attacks CVSS 4.0HIGH 7.7
- TI-2026-24402 Missing CSRF Protection on Administrative Endpoints in Nexxt Nebula 300+ CVSS 4.0HIGH 7.2
- TI-2026-24403 Plaintext Storage of Credentials in Configuration Backup in Nexxt Nebula 300+ CVSS 4.0MEDIUM 6.8
Sources
- CVE-2026-31848 · CVE Program
- CVE-2026-31848 · NVD
- FIRST EPSS
- GHSA-7xw4-69gx-5gch · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences