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Code InjectionWeakness · CWE-94

CVE-2026-12257

CRITICAL · 9.3 CVSS v4.0 Published 2026-07-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click 5 weeks old

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
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.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

Mura CMS versions before 10.0.712 have an unauthenticated RCE vulnerability in the /index.cfm/_api/json/v1/default endpoint. The 'method' parameter in POST requests is not validated before ColdFusion engine processing, allowing arbitrary CFML expression injection and malicious Java object instantiation.

MitigationUpgrade to Mura CMS version 10.0.712 or later. As an interim control, restrict or block external access to the /index.cfm/_api/ endpoint via WAF or network-level filtering until the patch is applied.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
Authentication
X
User interaction
None
Scope
X

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify Mura CMS installation
    Locate the Mura CMS instance and determine its version. Check the administrator dashboard (typically at /admin), the site footer, or configuration files for the version number.
    Affected if The version displayed is before 10.0.712 (e.g., 10.0.500, 9.x, etc.)
  2. Confirm version number against advisory
    Compare the identified version to 10.0.712. All versions prior to 10.0.712 are affected by this vulnerability.
    Affected if The installed version is any build number lower than 10.0.712, regardless of whether it is a 10.x or 9.x release.
  3. Verify API endpoint exposure
    Check if the /index.cfm/_api/json/v1/default endpoint is reachable from the network. Attempt a simple GET or POST request to this URL from an untrusted network perspective.
    Affected if The endpoint is accessible externally without authentication and the version is below 10.0.712.
  4. Check unauthenticated API access
    Inspect whether the /index.cfm/_api/ path permits unauthenticated requests. Review network-level access controls, web server configuration, or WAF rules governing this path.
    Affected if External unauthenticated access to /index.cfm/_api/ is permitted and the Mura CMS version is below 10.0.712.

You are affected if Mura CMS version is below 10.0.712 and the /index.cfm/_api/ endpoint is accessible without authentication.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Upgrade to Mura CMS version 10.0.712 or later. As an interim control, restrict or block external access to the /index.cfm/_api/ endpoint via WAF or network-level filtering until the patch is applied.

Recommended fix High confidence

Mura CMS version 10.0.712 or later

  1. Upgrade Mura CMS to version 10.0.712 or later to remediate the RCE vulnerability
  2. If immediate upgrade is not possible, restrict network access to the /index.cfm/_api/json/v1/default endpoint using a web application firewall (WAF) or network-level access controls
  3. Review and monitor server logs for suspicious POST requests to the affected endpoint containing unexpected method parameter values
  4. After upgrading, verify the fix by testing that arbitrary CFML expressions can no longer be injected via the method parameter
Caveat Review Mura CMS 10.0.712 release notes for any breaking changes or configuration requirements before upgrading production systems

Generated from the published advisory — verify against the referenced sources before acting.

Have this fixed Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2026-12257 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data