SB20260417106 - Multiple vulnerabilities in Craft CMS



SB20260417106 - Multiple vulnerabilities in Craft CMS

Published: April 17, 2026

Security Bulletin ID SB20260417106
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Data manipulation

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 vulnerabilities.


1) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2026-27128)

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to escalate privileges.

The vulnerability exists due to a time-of-check time-of-use (TOCTOU) race condition in the token validation service when handling concurrent requests for limited-usage impersonation tokens. A remote user can send concurrent requests using a valid impersonation URL to escalate privileges.

Exploitation requires obtaining a non-expired impersonation URL via some other means and bypassing any rate-limiting rules in place.


2) Cross-site scripting (CVE-ID: CVE-2026-27126)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear


The vulnerability allows a remote user to execute arbitrary JavaScript in another user's browser.

The vulnerability exists due to cross-site scripting in editableTable.twig when rendering table fields with the html column type. A remote user can modify a field configuration to include a malicious payload to execute arbitrary JavaScript in another user's browser.

Exploitation requires an administrator account, allowAdminChanges to be enabled in production, and another user to view a page containing the malicious table field.


3) Cross-site scripting (CVE-ID: N/A)

CWE-ID: CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Clear


The vulnerability allows a remote user to execute arbitrary JavaScript in a victim's browser.

The vulnerability exists due to cross-site scripting in editableTable.twig when rendering row heading values in a table field. A remote user can inject a malicious row heading value to execute arbitrary JavaScript in a victim's browser.

Exploitation requires an administrator account and the allowAdminChanges setting to be enabled in production.


4) Server-Side Request Forgery (SSRF) (CVE-ID: CVE-2026-27129)

CWE-ID: CWE-918 - Server-Side Request Forgery (SSRF)

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to disclose sensitive information.

The vulnerability exists due to improper SSRF protection in GraphQL Asset mutation URL validation when resolving hostnames that have only AAAA records. A remote user can send a specially crafted GraphQL asset mutation with a URL that resolves only to an IPv6 address to disclose sensitive information.

Exploitation requires GraphQL schema permissions to create and edit assets, or a public GraphQL schema that is misconfigured with write permissions.


5) Time-of-check Time-of-use (TOCTOU) Race Condition (CVE-ID: CVE-2026-27127)

CWE-ID: CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a remote user to bypass SSRF protections and disclose sensitive information.

The vulnerability exists due to time-of-check time-of-use (TOCTOU) race condition in the GraphQL Asset mutation resolver when validating a hostname separately from the subsequent HTTP request. A remote user can supply a URL that uses DNS rebinding to bypass SSRF protections and disclose sensitive information.

Exploitation requires GraphQL schema permissions to create or edit assets, or a public schema that is misconfigured with write permissions.


Remediation

Install update from vendor's website.