Craft CMS's race condition in Token Service potentially allows for token usage greater than the token limit
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- None
- Attack complexity
- High
- Attack requirements
- Present
- Impact type
- —
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA and GitHub.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Craft CMS | cms | 4.5.0-RC1 to before 4.16.19; 5.0.0-RC1 to before 5.8.23 | 4.16.19, 5.8.23 | Patch available | CNA |
| — | craftcms/cms (Packagist) | 4.5.0-RC1 to before 4.16.19 | 4.16.19 | Patch available | GHSA-6fx5-5cw5-4897 |
| — | craftcms/cms (Packagist) | 5.0.0-RC1 to before 5.8.23 | 5.8.23 | Patch available | GHSA-6fx5-5cw5-4897 |
- cms VendorCraft CMS Affected 4.5.0-RC1 to before 4.16.19; 5.0.0-RC1 to before 5.8.23 Fixed in 4.16.19, 5.8.23 Patch available CNA
- craftcms/cms (Packagist) Vendor— Affected 4.5.0-RC1 to before 4.16.19 Fixed in 4.16.19 Patch available GHSA-6fx5-5cw5-4897
- craftcms/cms (Packagist) Vendor— Affected 5.0.0-RC1 to before 5.8.23 Fixed in 5.8.23 Patch available GHSA-6fx5-5cw5-4897
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:* | after 4.5.0, before 4.16.19; after 5.0.0, before 5.8.23 | Vulnerable | Craft CMS |
| cpe:2.3:a:craftcms:craft_cms:4.5.0:-:*:*:*:*:*:* | 4.5.0 | Vulnerable | Craft CMS |
| cpe:2.3:a:craftcms:craft_cms:4.5.0:rc1:*:*:*:*:*:* | 4.5.0 rc1 | Vulnerable | Craft CMS |
| cpe:2.3:a:craftcms:craft_cms:5.0.0:-:*:*:*:*:*:* | 5.0.0 | Vulnerable | Craft CMS |
| cpe:2.3:a:craftcms:craft_cms:5.0.0:rc1:*:*:*:*:*:* | 5.0.0 rc1 | Vulnerable | Craft CMS |
- cpe:2.3:a:craftcms:craft_cms:*:*:*:*:*:*:*:* Versions after 4.5.0, before 4.16.19; after 5.0.0, before 5.8.23 Vulnerable ·Craft CMS
- cpe:2.3:a:craftcms:craft_cms:4.5.0:-:*:*:*:*:*:* Versions 4.5.0 Vulnerable ·Craft CMS
- cpe:2.3:a:craftcms:craft_cms:4.5.0:rc1:*:*:*:*:*:* Versions 4.5.0 rc1 Vulnerable ·Craft CMS
- cpe:2.3:a:craftcms:craft_cms:5.0.0:-:*:*:*:*:*:* Versions 5.0.0 Vulnerable ·Craft CMS
- cpe:2.3:a:craftcms:craft_cms:5.0.0:rc1:*:*:*:*:*:* Versions 5.0.0 rc1 Vulnerable ·Craft CMS
Remediation
- Fix · CNA cms (craftcms) Fixed in 4.16.19, 5.8.23
- Fix · GHSA-6fx5-5cw5-4897 craftcms/cms (Packagist) Fixed in 4.16.19 Advisory →
- Fix · GHSA-6fx5-5cw5-4897 craftcms/cms (Packagist) Fixed in 5.8.23 Advisory →
Timeline
- 2026-10-02 Threatist record created from CVE-2026-27128
- 2026-10-03 Alias added: GHSA-6fx5-5cw5-4897
References
More Craft Cms vulnerabilities
- TI-2025-23503 Craft CMS Allows Remote Code Execution KEVCVSS 3.1CRITICAL 10.0
- TI-2024-37138 RCE when PHP `register_argc_argv` config setting is enabled in craftcms/cms KEVCVSS 4.0CRITICAL 9.3
- TI-2025-16994 Potential RCE with a compromised security key in craft/cms KEVCVSS 3.1HIGH 8.1
- TI-2025-24595 Craft CMS stores user-provided content in session files KEVCVSS 4.0MEDIUM 6.9
- TI-2023-22284 Craft CMS Remote Code Execution vulnerability CVSS 3.1CRITICAL 10.0
- TI-2024-25171 Craft CMS up to v3.7.31 was discovered to contain a SQL injection vulnerability via the GraphQL API endpoint. CVSS 3.1CRITICAL 9.8
Sources
- CVE-2026-27128 · CVE Program
- CVE-2026-27128 · NVD
- FIRST EPSS
- GHSA-6fx5-5cw5-4897 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences