What’s Vulnerable › Vulnerabilities

CVE-2026-84800: Craft CMS 5.0.0-RC1 before 5.10.11 File Overwrite via assets/replace-file

• Severity: high (CVSS 7.1 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-02 · updated 2026-09-02
• Weakness: CWE-862

Description

Craft CMS versions >= 5.0.0-RC1 and < 5.10.11 contain a missing authorization vulnerability in AssetsController::actionReplaceFile. When a request supplies sourceAssetId and targetFilename but omits assetId, the target asset is resolved by folder and filename after the permission checks execute, so the replacePeerFiles permission is never enforced. An authenticated low-privilege author with only the replaceFiles permission on a shared folder can overwrite the content of a peer's asset file (located in the same folder) with attacker-controlled bytes. Fixed in 5.10.11.

Affected products

• craftcms cms: from 5.0.0-RC1 before 5.10.11 — fixed in 5.10.11

How to fix

Upgrade to a fixed version: craftcms cms 5.10.11. Check the vendor advisory for mitigations.

References

• https://github.com/craftcms/cms/security/advisories/GHSA-329j-cx85-8r56
• https://www.vulncheck.com/advisories/craft-cms-5.0.0-rc1-before-5.10.11-file-overwrite-via-assets-replace-file

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