{"id":"CVE-2026-31847","aliases":["EUVD-2026-14413","GHSA-892q-6j8f-3q9c"],"status":"published","title":"Hidden Functionality Enables Remote Telnet Activation via /goform/setSysTools in Nexxt Nebula 300+","description":"Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManageEn=true and telnetPwd, an authenticated attacker can activate a Telnet service on port 23.","severity":{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:H/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":0.00422,"percentile":0.37001,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-912"],"published":"2026-03-23T12:07:05Z","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-2026-31847"},{"url":"https://www.nexxtsolutions.com/connectivity/internal-products/ARN02304U6"},{"url":"https://github.com/advisories/GHSA-892q-6j8f-3q9c"}],"sources":{"cve":[{"id":"CVE-2026-31847","title":"Hidden Functionality Enables Remote Telnet Activation via /goform/setSysTools in Nexxt Nebula 300+","description":"Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManageEn=true and telnetPwd, an authenticated attacker can activate a Telnet service on port 23.","status":"published","published":"2026-03-23T12:07:05.062Z","modified":"2026-08-10T11:43:39.725Z","cvss":[{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N","level":"high","assessor":"cna"}],"cwes":["CWE-912"],"updated_at":"2026-11-02T14:19:50.92611Z"}],"euvd":[{"id":"EUVD-2026-14413","description":"Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManageEn=true and telnetPwd, an authenticated attacker can activate a Telnet service on port 23.","status":"published","published":"2026-03-23T12:07:05Z","modified":"2026-08-10T11:43:39Z","cvss":[{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:H/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-892q-6j8f-3q9c","title":"Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware...","description":"Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. Once enabled, the service exposes a privileged diagnostic management interface over the network, increasing the attack surface and enabling further compromise of the device.","status":"published","published":"2026-03-23T15:30:44Z","modified":"2026-04-29T18:31:31Z","cvss":[{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:H/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"},{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-912"],"updated_at":"2026-11-02T15:07:51.219984Z"}],"nvd":[{"id":"CVE-2026-31847","description":"Hidden functionality in the /goform/setSysTools endpoint in Nexxt Solutions Nebula 300+ firmware through version 12.01.01.37 allows remote enablement of a Telnet service. By sending a crafted POST request with parameters such as telnetManageEn=true and telnetPwd, an authenticated attacker can activate a Telnet service on port 23.","status":"published","published":"2026-03-23T13:16:30.32Z","modified":"2026-08-10T12:17:15.34Z","cvss":[{"version":"4.0","score":8.5,"vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:H/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":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-912"],"updated_at":"2026-11-02T14:12:10.568062Z"}]}}