CVE-2026-27128

Published Feb 24, 2026

Last updated 10 days ago

CVSS medium 6.9
graphql

Overview

Description
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.
Source
security-advisories@github.com
NVD status
Analyzed
Products
craft_cms

Risk scores

CVSS 4.0

Type
Secondary
Base score
6.9
Impact score
-
Exploitability score
-
Vector string
CVSS:4.0/AV:N/AC:H/AT:P/PR:H/UI:N/VC:H/VI:N/VA:N/SC:H/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
Severity
MEDIUM

CVSS 3.1

Type
Primary
Base score
4.8
Impact score
2.7
Exploitability score
1.7
Vector string
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Severity
MEDIUM

Weaknesses

security-advisories@github.com
CWE-367

Social media

Hype score
Not currently trending

Configurations

Related CVEs

  1. Craft is a content management system (CMS). Prior to 5.9.0-beta.2 and 4.17.0-beta.2, the actionSendActivationEmail() endpoint is accessible to unauthenticated users and does not require a permission check for pending users. An attacker with no prior access can trigger activation emails for any pending user account by knowing or guessing the user ID. If the attacker controls the target user’s email address, they can activate the account and gain access to the system. This vulnerability is fixed in 5.9.0-beta.2 and 4.17.0-beta.2.•CVE-2026-29069
  2. Craft is a content management system (CMS). Prior to 4.17.0-beta.1 and 5.9.0-beta.1, the entry creation process allows for Mass Assignment of the authorId attribute. A user with "Create Entries" permission can inject the authorIds[] (or authorId) parameter into the POST request, which the backend processes without verifying if the current user is authorized to assign authorship to others. Normally, this field is not present in the request for users without the necessary permissions. By manually adding this parameter, an attacker can attribute the new entry to any user, including Admins. This effectively "spoofs" the authorship. This vulnerability is fixed in 4.17.0-beta.1 and 5.9.0-beta.1.•CVE-2026-28781
  3. Craft is a content management system (CMS). Prior to 4.17.0-beta.1 and 5.9.0-beta.1, the GraphQL directive @parseRefs, intended to parse internal reference tags (e.g., {user:1:email}), can be abused by both authenticated users and unauthenticated guests (if a Public Schema is enabled) to access sensitive attributes of any element in the CMS. The implementation in Elements::parseRefs fails to perform authorization checks, allowing attackers to read data they are not authorized to view. This vulnerability is fixed in 4.17.0-beta.1 and 5.9.0-beta.1.•CVE-2026-28696
  4. Craft is a content management system (CMS). Prior to 5.8.22 and 4.16.18, it is possible to craft a malicious payload using the Twig map filter in text fields that accept Twig input under Settings in the Craft control panel or using the System Messages utility, which could lead to a RCE. For this to work, you must have administrator access to the Craft Control Panel, and allowAdminChanges must be enabled for this to work, which is against our recommendations for any non-dev environment. Alternatively, you can have a non-administrator account with allowAdminChanges disabled, but you have access to the System Messages utility. Users should update to the patched versions (5.8.22 and 4.16.18) to mitigate the issue.•CVE-2026-28784
  5. Craft is a content management system (CMS). Prior to 5.9.0-beta.1 and 4.17.0-beta.1, Craft CMS implements a blocklist to prevent potentially dangerous PHP functions from being called via Twig non-Closure arrow functions. In order to be able to successfully execute this attack, you need to either have allowAdminChanges enabled on production, or a compromised admin account, or an account with access to the System Messages utility. Several PHP functions are not included in the blocklist, which could allow malicious actors with the required permissions to execute various types of payloads, including RCEs, arbitrary file reads, SSRFs, and SSTIs. This vulnerability is fixed in 5.9.0-beta.1 and 4.17.0-beta.1.•CVE-2026-28783

References

Sources include official advisories and independent security research.