GHSA-957r-qf9p-67xw: craftcms/cms (CVE-2026-72779)

Package	Ecosystem	Affected	Fixed in
craftcms/cms	Packagist	>=5.0.0-RC1, <5.10.6 \|\| >=4.0.0-RC1, <4.18.2	5.10.6, 4.18.2

Machine-written summary

Summary written by Claude Haiku from the source advisory. Not reviewed by a person.

Craft CMS (Packagist craftcms/cms) versions from 4.0.0-RC1 before 4.18.2 and from 5.0.0-RC1 before 5.10.6 are affected by an arbitrary file read flaw. The Twig create() function, added in 5.9.0, can instantiate PHP classes such as SplFileObject from non-sandboxed template contexts like entry type title and URI formats, because the blocklist does not cover that class. An attacker needs admin access with allowAdminChanges enabled, and can then read arbitrary server files, such as .env secrets, with file contents shown as entry titles. Upgrade to 4.18.2 or 5.10.6.

Written 31 Oct 2026.

Not analysed yet

We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check.

Severity and exploitation

Score	Rating	CVSS	Vector	Source
8.7	High	4.0	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N	CNA (VulnCheck)

CISA KEV Not listed.
EPSS 0.0038, the 31st percentile, on 5 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 14:06 UTC First seen by agentprime
31 Oct 2026, 14:06 UTC Confirmed by OSV

Sources

Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code.