Craft CMS up to 4.16.18/5.8.22 getTokenRoute toctou

Summaryinfo

A vulnerability has been found in Craft CMS up to 4.16.18/5.8.22 and classified as problematic. The impacted element is the function getTokenRoute. This manipulation causes toctou. This vulnerability is tracked as CVE-2026-27128. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Craft CMS up to 4.16.18/5.8.22. It has been declared as problematic. Affected by this vulnerability is the function getTokenRoute. The manipulation with an unknown input leads to a toctou vulnerability. The CWE definition for the vulnerability is CWE-367. The product checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the product to perform invalid actions when the resource is in an unexpected state. As an impact it is known to affect confidentiality. The summary by CVE is:

Craft is a content management system (CMS). In versions 4.5.0-RC1 through 4.16.18 and 5.0.0-RC1 through 5.8.22, a Time-of-Check-Time-of-Use (TOCTOU) race condition exists in Craft CMS’s token validation service for tokens that explicitly set a limited usage. The `getTokenRoute()` method reads a token’s usage count, checks if it’s within limits, then updates the database in separate non-atomic operations. By sending concurrent requests, an attacker can use a single-use impersonation token multiple times before the database update completes. To make this work, an attacker needs to obtain a valid user account impersonation URL with a non-expired token via some other means and exploit a race condition while bypassing any rate-limiting rules in place. For this to be a privilege escalation, the impersonation URL must include a token for a user account with more permissions than the current user. Versions 4.16.19 and 5.8.23 patch the issue.

The advisory is shared at github.com. This vulnerability is known as CVE-2026-27128 since 02/17/2026. The exploitation appears to be difficult. The attack can be launched remotely. Additional levels of successful authentication are required for exploitation. Technical details are known, but no exploit is available.

Upgrading to version 4.16.19 or 5.8.23 eliminates this vulnerability. Applying the patch 3e4afe18279951c024c64896aa2b93cda6d95fdf is able to eliminate this problem. The bugfix is ready for download at github.com. The best possible mitigation is suggested to be upgrading to the latest version.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

• Content Management System

Vendor

• Craft

Name

• CMS

Version

• 4.16.0
• 4.16.1
• 4.16.2
• 4.16.3
• 4.16.4
• 4.16.5
• 4.16.6
• 4.16.7
• 4.16.8
• 4.16.9
• 4.16.10
• 4.16.11
• 4.16.12
• 4.16.13
• 4.16.14
• 4.16.15
• 4.16.16
• 4.16.17
• 4.16.18
• 5.8.0
• 5.8.1
• 5.8.2
• 5.8.3
• 5.8.4
• 5.8.5
• 5.8.6
• 5.8.7
• 5.8.8
• 5.8.9
• 5.8.10
• 5.8.11
• 5.8.12
• 5.8.13
• 5.8.14
• 5.8.15
• 5.8.16
• 5.8.17
• 5.8.18
• 5.8.19
• 5.8.20
• 5.8.21
• 5.8.22

License

• free

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Discussion