{"id":"CVE-2026-33923","title":"Update bundle signature bypass in Guardian/CMC before 26.4.0","summary":"A signature verification vulnerability was discovered in the update installation functionality due to inconsistent validation of the update bundle contents. An attacker with administrative privileges can remotely supply a crafted update …","severity":"high","cvss":7.2,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-347"],"vendor":"Nozomi Networks","product":"Guardian","affected":["Guardian < 26.4.0","CMC < 26.4.0"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2026-10-29T12:19:57.938573Z"},"published":"2026-10-29","updated":"2026-10-29","sourceUpdated":"2026-10-29T12:36:53.310Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-33923","references":[{"url":"https://security.nozominetworks.com/NN-2026:21-01"}],"tags":["cve.org"],"epss":0.00227,"epssPercentile":0.13458,"ingestedAt":"2026-11-01T18:59:04.469Z","slug":"CVE-2026-33923","body":"## Overview\n\nA signature verification vulnerability was discovered in the update installation functionality due to inconsistent validation of the update bundle contents. An attacker with administrative privileges can remotely supply a crafted update bundle that passes signature verification but runs an unsigned script when the bundle is installed. The script runs with root privileges, allowing the attacker to read or modify sensitive data, change the appliance configuration, or shut down the appliance.\n\n## Affected\n\n- `Guardian < 26.4.0`\n- `CMC < 26.4.0`\n\n## Remediation\n\nUpgrade to v26.4.0 or later.\n\n### Workarounds\n\nUse internal firewall features to limit access to the web management interface.\nReview all accounts with administrative privileges and delete unnecessary ones.\nInstall update bundles only when they come from trusted Nozomi Networks sources.","depth":"twilight","depthScore":40,"depthScoreParts":{"impact":39.6,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}