CVE-2026-33923

Update bundle signature bypass in Guardian/CMC before 26.4.0

Published Oct 29, 2026 CVSS 4.0 · 7.5 High EPSS < 1% KEV · Not listed
Description
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 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.

Remediation

Vendor Solution

Upgrade to v26.4.0 or later.


Vendor Workaround

Use internal firewall features to limit access to the web management interface.

Tracking

Sign in to view the affected projects.

Advisories

No advisories available
History
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 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 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.
Title Update bundle signature bypass in Guardian/CMC before 26.4.0
First Time appeared Nozomi Networks
Nozomi Networks cmc
Nozomi Networks guardian
Weaknesses CWE-347
CPEs cpe:2.3:a:nozomi_networks:cmc:*:*:*:*:*:*:*:*
cpe:2.3:a:nozomi_networks:guardian:*:*:*:*:*:*:*:*
Vendors & Products Nozomi Networks
Nozomi Networks cmc
Nozomi Networks guardian
References
Metrics cvssV3_1

{'score': 7.2, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H'}

cvssV4_0

{'score': 7.5, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Nozomi
Published
Updated
Oct 29, 2026, 12:36 PM
Reserved
Mar 24, 2026, 4:06 PM
Status
Awaiting Analysis
Published
Oct 29, 2026, 11:17 AM
Modified
Oct 29, 2026, 3:59 PM