CVE-2026-31857
RCE in Craft CMS via unsandboxed Twig render in condition rules.
Is CVE-2026-31857 being exploited?
Not confirmed. CVE-2026-31857 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 0.66% probability of exploitation in the next 30 days.
How severe is CVE-2026-31857?
CVE-2026-31857 is rated High with a CVSS score of 8.1. 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-2026-31857?
Yes. A fix has been recorded for CVE-2026-31857. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-31857 affect?
CVE-2026-31857 affects Craft CMS <5.9.9, Craft CMS <4.17.4. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-31857?
Update to 5.9.9 or 4.17.4.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated CP user can achieve full RCE by crafting a condition rule using unsandboxed Twig rendering, bypassing hardening.
Immediate action required
- affected>= 5.0.0-RC1 and < 5.9.9
- affected>= 4.0.0-beta.1 and < 4.17.4
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.