# CVE-2025-51726: Weak cryptography in n/a

> Weak SHA-1 signing and missing ASLR in the CyberGhost VPN installer allow attackers to forge signatures and exploit memory corruption for code execution.

- **Severity:** High 8.4 (`CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 4 Aug 2025
- **Updated:** 5 Aug 2025
- **Also known as:** GHSA-hxjr-jx9x-w63w

## What is CVE-2025-51726?

CVE-2025-51726 is a high-severity vulnerability in n/a, published on 4 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

CyberGhostVPNSetup.exe (Windows installer) is signed using the weak cryptographic hash algorithm SHA-1, which is vulnerable to collision attacks. This allows a malicious actor to craft a fake installer with a forged SHA-1 certificate that may still be accepted by Windows signature verification mechanisms, particularly on systems without strict SmartScreen or trust policy enforcement. Additionally, the installer lacks High Entropy Address Space Layout Randomization (ASLR), as confirmed by BinSkim (BA2015 rule) and repeated WinDbg analysis. The binary consistently loads into predictable memory ranges, increasing the success rate of memory corruption exploits. These two misconfigurations, when combined, significantly lower the bar for successful supply-chain style attacks or privilege escalation through fake installers.

Weakness: CWE-327 (Use of a Broken or Risky Cryptographic Algorithm)

## Which versions are affected by CVE-2025-51726?


## How do I fix CVE-2025-51726?

No fix has been published for CVE-2025-51726 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-51726 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-51726 exists.

Public exploit code:

- https://github.com/meisterlos/CVE-2025-51726 (github_poc): https://github.com/meisterlos/CVE-2025-51726

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-51726 and fix it if it is affected.

What it is: CVE-2025-51726 is a high-severity vulnerability in n/a, published on 4 Aug 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2025-51726 exists.

Affected product: n/a. 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-2025-51726/ (Markdown: https://insights.sbomify.com/CVE-2025-51726/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-51726
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-51726
- OSV: https://osv.dev/vulnerability/CVE-2025-51726

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-51726/
Summaries are generated and may contain mistakes; the official description above is the record.