CVE-2026-12257
Unauthenticated RCE in Mura CMS via unsanitized 'method' param in JSON API
Is CVE-2026-12257 being exploited?
Not confirmed. CVE-2026-12257 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.70% probability of exploitation in the next 30 days.
How severe is CVE-2026-12257?
CVE-2026-12257 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-12257?
Yes. A fix has been recorded for CVE-2026-12257. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-12257 affect?
CVE-2026-12257 affects Mura CMS < 10.0.712, ColdFusion application servers hosting Mura. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-12257?
Upgrade Mura CMS to >=10.0.712; restrict endpoint, apply WAF rules, review logs.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote code execution: attacker can inject CFML and instantiate Java objects via POST 'method' param, enabling full server compromise, data theft, or lateral movement.
Immediate action required
- affected10.0.712
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.