GHSA-xv9m-fm3w-8w5x: october/system (CVE-2026-46696)

October CMS: Safe Mode Sandbox Bypass via Session Store and Forwarded Builder Calls

CVSS 3.3 LowEPSS 0.0027 · 19th percentile

Published by the GitHub Advisory Database at 14 Sept 2026, 16:02 UTC. agentprime has not analysed this yet, so whether it affects any app is not known.

Package	Ecosystem	Affected	Fixed in
october/system	Packagist	<3.7.17 \|\| >=4.0.0, <4.2.23	3.7.17, 4.2.23

Identifiers

GHSA-xv9m-fm3w-8w5x · CVE-2026-46696 · PKSA-m19v-7rfv-5pmv

Weakness (CWE)

CWE-269 · CWE-284

Machine-written summary

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

The october/system package in October CMS, versions below 3.7.17 and from 4.0.0 before 4.2.23, has a Twig sandbox bypass when `cms.safe_mode` is enabled. A backend user with CMS markup editing access on such a site can chain calls to read arbitrary database values and forge a backend session as an existing superuser. Upgrade to 3.7.17 or 4.2.23.

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
3.3	Low	3.1	CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:L/I:L/A:N	CNA (GitHub_M)

CISA KEV Not listed.
EPSS 0.0027, the 19th percentile, on 12 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days.

Timeline

31 Oct 2026, 13:56 UTC First seen by agentprime
31 Oct 2026, 13:56 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.