Summary
Craft CMS has a potential information disclosure vulnerability in preview tokens
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That token can then be used by the attacker (without authentication) to access previewed/unpublished content tied to the victim’s authorized preview scope.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
canonicalIdand public URL path of that entry.
1) Attacker prepares a fixed token
Use any 32-character value, for example:
aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa
2) CSRF victim into minting that token
Send the victim a link (or top-level redirect) such as:
https://TARGET/actions/preview/create-token?elementType=craft%5Celements%5CEntry&canonicalId=123&siteId=1&previewToken=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa&redirect=https%3A%2F%2FTARGET%2F
If the victim is logged in and authorized for previewElement:123, Craft creates that exact token.
3) Attacker accesses preview content unauthenticated
curl -i 'https://TARGET/news/known-entry-slug?token=aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa'
Expected vulnerable behavior:
- Response renders preview/unpublished state (draft/provisional context), not just normal public content.
Impact
- CSRF-based minting of attacker-known preview tokens.
- Unauthorized access to draft/provisional/revision content via token replay.
- Stealthy one-click exploitation against logged-in editors/admins.
- No dependency on forwarded-host poisoning.
The application does not adequately verify the identity of a user, device, or process before granting access. Typical impact: unauthorized access to functions or data reserved for authenticated parties.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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craftcms/cms to 4.17.4 or later; craftcms/cms to 5.9.7 or later
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2026-29113? CVE-2026-29113 is a low-severity improper authentication vulnerability in craftcms/cms (composer), affecting versions >= 4.0.0-RC1, < 4.17.3. It is fixed in 4.17.4, 5.9.7. The application does not adequately verify the identity of a user, device, or process before granting access.
- Which versions of craftcms/cms are affected by CVE-2026-29113? craftcms/cms (composer) versions >= 4.0.0-RC1, < 4.17.3 is affected.
- Is there a fix for CVE-2026-29113? Yes. CVE-2026-29113 is fixed in 4.17.4, 5.9.7. Upgrade to this version or later.
- Is CVE-2026-29113 exploitable, and should I be worried? Whether CVE-2026-29113 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-29113 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-29113?
- Upgrade
craftcms/cmsto 4.17.4 or later - Upgrade
craftcms/cmsto 5.9.7 or later
- Upgrade