CVE-2026-84800
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.
What this means for your business
- An attacker can use it remotely, over a network, with an ordinary user login, and without anyone at your company clicking anything.
- FIRST's prediction model gives it a 0.2% chance of attack attempts being seen in the next 30 days, ranking above 10% of all known flaws.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
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Scoring
- CVSS
- 7.1 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:L- CVSS v4
- 7.1
- Weakness
- CWE-862
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-02
- Last modified
- 2026-09-02
- Sources
- NVD