# CVE-2026-33923: Update bundle signature bypass in Guardian/CMC before 26.4.0


- **Severity:** High 7.5 (`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`)
- **Exploited in the wild:** Not known
- **Fix available:** No
- **Published:** 29 Oct 2026
- **Updated:** 29 Oct 2026
- **Also known as:** GHSA-9v7w-2fr3-g7q8

## What is CVE-2026-33923?

CVE-2026-33923 is a high-severity vulnerability in Nozomi Networks CMC, published on 29 Oct 2026. 

### Official 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.

Weakness: CWE-347 (Improper Verification of Cryptographic Signature)

## Which versions are affected by CVE-2026-33923?


## How do I fix CVE-2026-33923?

No fix has been published for CVE-2026-33923 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-33923 being exploited?

There is no known exploitation of CVE-2026-33923 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33923 and fix it if it is affected.

What it is: CVE-2026-33923 is a high-severity vulnerability in Nozomi Networks CMC, published on 29 Oct 2026. 
Exploitation: There is no known exploitation of CVE-2026-33923 in the wild and no public exploit code.

Affected product: Nozomi Networks CMC. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-33923/ (Markdown: https://insights.sbomify.com/CVE-2026-33923/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33923
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33923
- OSV: https://osv.dev/vulnerability/CVE-2026-33923

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33923/
Summaries are generated and may contain mistakes; the official description above is the record.