# CVE-2026-12257: Remote code execution in Mura Software’s CMS

> Remote attackers can execute arbitrary code by injecting CFML expressions via the method parameter in Mura CMS.

- **Severity:** Critical 9.3 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/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:** 13 Jul 2026
- **Updated:** 13 Jul 2026
- **Also known as:** GHSA-h3q4-w5v4-67hw

## What is CVE-2026-12257?

CVE-2026-12257 is a critical code injection vulnerability in Mura Software CMS, published on 13 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Versions of Mura CMS prior to 10.0.712 contain a critical remote code execution (RCE) vulnerability. The flaw is located in the endpoint “/index.cfm/_api/json/v1/default”, where the “method” parameter in POST requests is not properly validated or sanitised before being processed by the ColdFusion engine. As a result, a remote attacker could exploit this vulnerability to inject and execute arbitrary CFML (ColdFusion Markup Language) expressions and instantiate malicious Java objects, thereby compromising the system’s security.

Weakness: CWE-94 (Improper Control of Generation of Code)

## Which versions are affected by CVE-2026-12257?


## How do I fix CVE-2026-12257?

No fix has been published for CVE-2026-12257 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-12257 being exploited?

There is no known exploitation of CVE-2026-12257 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-12257 and fix it if it is affected.

What it is: CVE-2026-12257 is a critical code injection vulnerability in Mura Software CMS, published on 13 Jul 2026. 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-2026-12257 in the wild and no public exploit code.

Affected product: Mura Software CMS. 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-2026-12257/ (Markdown: https://insights.sbomify.com/CVE-2026-12257/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-12257
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-12257
- OSV: https://osv.dev/vulnerability/CVE-2026-12257

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-12257/
Summaries are generated and may contain mistakes; the official description above is the record.