# CVE-2021-47712: Kentico Xperience <= 12.0.102 URL Hashing Cryptography Vulnerability

> Attackers can manipulate URL hash values due to weak cryptography, potentially bypassing security controls in Kentico Xperience.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 18 Dec 2025
- **Updated:** 18 Dec 2025
- **Also known as:** GHSA-9jrm-mcr7-5p6m

## What is CVE-2021-47712?

CVE-2021-47712 is a medium-severity vulnerability in Kentico Xperience, published on 18 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

A cryptography vulnerability in Kentico Xperience allows attackers to potentially manipulate URL hash values through existing hashing mechanisms. The hotfix introduces an additional security layer to prevent hash value reuse and potential exploitation.

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

## Which versions are affected by CVE-2021-47712?

It affects 1 product.


Products: Kentico Xperience.

## How do I fix CVE-2021-47712?

No fix has been published for CVE-2021-47712 yet. Limit exposure of the affected software until one is available.

## Is CVE-2021-47712 being exploited?

There is no known exploitation of CVE-2021-47712 in the wild and no public exploit code.

## Other vulnerabilities in Kentico Xperience

- [CVE-2025-2746](https://insights.sbomify.com/CVE-2025-2746/): Kentico Xperience CMS Authentication Bypass Using an Alternate Path or Channel (critical 9.8, exploited in the wild)
- [CVE-2025-2747](https://insights.sbomify.com/CVE-2025-2747/): Kentico Xperience CMS Authentication Bypass Using an Alternate Path or Channel (critical 9.8, exploited in the wild)
- [CVE-2019-10068](https://insights.sbomify.com/CVE-2019-10068/): Kentico Xperience Deserialization of Untrusted Data (critical 9.8, exploited in the wild)
- [CVE-2025-2749](https://insights.sbomify.com/CVE-2025-2749/): Kentico Xperience Path Traversal (high 7.2, exploited in the wild)
- [CVE-2017-17736](https://insights.sbomify.com/CVE-2017-17736/): Missing authorization in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2021-47712 and fix it if it is affected.

What it is: CVE-2021-47712 is a medium-severity vulnerability in Kentico Xperience, published on 18 Dec 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2021-47712 in the wild and no public exploit code.

Affected product: Kentico Xperience. 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-2021-47712/ (Markdown: https://insights.sbomify.com/CVE-2021-47712/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2021-47712
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2021-47712
- OSV: https://osv.dev/vulnerability/CVE-2021-47712

---
From sbomify Insights: https://insights.sbomify.com/CVE-2021-47712/
Summaries are generated and may contain mistakes; the official description above is the record.