CVE-2026-28781
published 2026-03-04CVE-2026-28781: 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…
PriorityP338medium6.5CVSS 3.1
AVNACLPRLUINSUCNIHAN
EPSS
0.33%
24.4th percentile
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.
Affected
8 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| craftcms | cms | — | — |
| craftcms | cms | — | — |
| craftcms | cms | >= 4.0.0-RC1 < 4.17.0-beta.1 | 4.17.0-beta.1 |
| craftcms | cms | >= 5.0.0-RC1 < 5.9.0-beta.1 | 5.9.0-beta.1 |
| craftcms | craft_cms | < 4.17.0 | 4.17.0 |
| craftcms | craft_cms | < 5.9.0 | 5.9.0 |
| craftcms | craft_cms | — | — |
| craftcms | craft_cms | — | — |
CVSS provenance
nvdv3.16.5MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N
nvdv4.07.1HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/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
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OSV
Craft CMS: Entries Authorship Spoofing via Mass Assignment
osv·2026-03-03
CVE-2026-28781 [MEDIUM] Craft CMS: Entries Authorship Spoofing via Mass Assignment
Craft CMS: Entries Authorship Spoofing via Mass Assignment
## Description
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.
## Proof of Concept
### Prerequisites
- A user account with "Create Entries" permission for a section.
- Victim's account ID (e.g., `1` for the default Admin).
#
GHSA
Craft CMS: Entries Authorship Spoofing via Mass Assignment
ghsa·2026-03-03
CVE-2026-28781 [MEDIUM] CWE-639 Craft CMS: Entries Authorship Spoofing via Mass Assignment
Craft CMS: Entries Authorship Spoofing via Mass Assignment
## Description
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.
## Proof of Concept
### Prerequisites
- A user account with "Create Entries" permission for a section.
- Victim's account ID (e.g., `1` for the default Admin).
#
No detection rules found.
No public exploits indexed.
2026-03-04
Published