{"id":"CVE-2026-31848","aliases":["EUVD-2026-14415","GHSA-7xw4-69gx-5gch"],"status":"published","title":"Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+","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.","severity":{"version":"4.0","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","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00279,"percentile":0.20631,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-312"],"published":"2026-03-23T12:09:30Z","modified":"2026-08-10T12:17:15Z","products":[{"vendor":"nexxt solutions","product":"nebula 300+"},{"vendor":"nexxtsolutions","product":"nebula300plus_firmware"}],"references":[{"url":"https://www.nexxtsolutions.com/connectivity/internal-products/ARN02304U6/","tags":["third-party-advisory","Product"]},{"url":"https://nexxt-connectivity-frontend.s3.amazonaws.com/media/docs/Nebula300+_v12.01.01.37.zip","tags":["third-party-advisory","Product"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-31848"},{"url":"https://www.nexxtsolutions.com/connectivity/internal-products/ARN02304U6"},{"url":"https://github.com/advisories/GHSA-7xw4-69gx-5gch"}],"sources":{"cve":[{"id":"CVE-2026-31848","title":"Reversible ecos_pw Cookie Allows Authentication Bypass in Nexxt Nebula 300+","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.","status":"published","published":"2026-03-23T12:09:30.338Z","modified":"2026-08-10T11:43:41.847Z","cvss":[{"version":"4.0","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","level":"high","assessor":"cna"}],"cwes":["CWE-312"],"updated_at":"2026-11-02T14:19:50.92611Z"}],"euvd":[{"id":"EUVD-2026-14415","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.","status":"published","published":"2026-03-23T12:09:30Z","modified":"2026-08-10T11:43:41Z","cvss":[{"version":"4.0","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","level":"high"}],"updated_at":"2026-11-02T18:02:06.086083Z"}],"ghsa":[{"id":"GHSA-7xw4-69gx-5gch","title":"Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 stores administrative...","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.","status":"published","published":"2026-03-23T15:30:44Z","modified":"2026-04-29T18:32:36Z","cvss":[{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical"},{"version":"4.0","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/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","level":"high"}],"cwes":["CWE-312"],"updated_at":"2026-11-02T15:07:51.754992Z"}],"nvd":[{"id":"CVE-2026-31848","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.","status":"published","published":"2026-03-23T13:16:30.49Z","modified":"2026-08-10T12:17:15.48Z","cvss":[{"version":"4.0","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/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","level":"high","assessor":"secondary"},{"version":"3.1","score":9.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","level":"critical","assessor":"primary"}],"cwes":["CWE-312"],"updated_at":"2026-11-02T14:12:10.568062Z"}]}}