Craft CMS has a potential information disclosure vulnerability in preview tokens

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS 4.0

2.3 · CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/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 · score source

EPSS

• CVE-2026-29113: 0.18% estimated exploitation activity in the next 30 days; percentile 8.20 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Craft CMS has a CSRF issue in the preview token endpoint at /actions/preview/create-token. The endpoint accepts an attacker-supplied previewToken. Because the action does not require POST and does not enforce a CSRF token, an attacker can force a logged-in victim editor to mint a preview token chosen by the attacker. That token can then be used by the attacker (without authentication) to access previewed/unpublished content tied to the victim’s authorized preview scope. --- Preconditions - Victim is logged in to Craft control panel. - Victim has active preview authorization in session for target content (e.g., opened/edited an entry). - The attacker must know the target’s canonicalId and public URL path of that entry. 1) Attacker prepares a fixed token Use any 32-character value, for example: 2) CSRF victim into minting that token Send the victim a link (or top-level redirect) such as: If the victim is logged in and authorized for previewElement:123, Craft creates that exact…

Published by the source

10 Mar 2026, 18:22 UTC

Last modified by the source

2 Sep 2026, 13:35 UTC

Source last checked

26 Oct 2026, 14:53 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-vg3j-hpm9-8v5v

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# Patch Next advisory brief: CVE-2026-29113

Advisory: Craft CMS has a potential information disclosure vulnerability in preview tokens
IDs: CVE-2026-29113, GHSA-vg3j-hpm9-8v5v
Record: https://patchnext.com/advisories/cve-2026-29113 (revision 1, source checked 26 Oct 2026, 14:53 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Low (CVSS 2.3)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: craftcms/cms 5.9.7, 4.17.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist craftcms/cms: affected >= 4.0.0-RC1, < 4.17.3; >= 5.0.0-RC1, < 5.9.7; fixed in 4.17.3, 5.9.7

## Suggested inspection (read-only)
- Packagist craftcms/cms: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on craftcms/cms.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-vg3j-hpm9-8v5v (GitHub-reviewed advisory GHSA-vg3j-hpm9-8v5v lists affected ranges: Packagist craftcms/cms >=4.0.0-RC1 =5.0.0-RC1 <5.9.7)

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