# CVE-2026-28781: Craft Affected by Entries Authorship Spoofing via Mass Assignment > Attackers with entry creation permissions can spoof authorship by injecting authorId parameters, attributing content to unauthorized users like admins. - **Severity:** High 7.1 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N`) - **Exploited in the wild:** Not known - **Login needed:** Any signed-in user - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** Yes - **Published:** 4 Mar 2026 - **Updated:** 4 Mar 2026 - **Also known as:** GHSA-2xfc-g69j-x2mp ## What is CVE-2026-28781? CVE-2026-28781 is a high-severity vulnerability in Craftcms Craft Cms, published on 4 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim. ### Official description 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. Weakness: CWE-915 (Improperly Controlled Modification of Dynamically-Determined Object Attributes), CWE-639 (Authorization Bypass Through User-Controlled Key) ## Which versions are affected by CVE-2026-28781? 4 open source packages ship an affected version, including craftcms/cms. It affects 1 product. | Package | Ecosystem | Affected | Fixed in | | --- | --- | --- | --- | | `craftcms/cms` | Packagist | From 4.0.0-RC1 | 4.17.0-beta.1 | | `craftcms/cms` | Packagist | From 4.0.0-RC1 | 4.17.0-beta.1 | | `craftcms/cms` | Packagist | From 5.0.0-RC1 | 5.9.0-beta.1 | | `craftcms/cms` | Packagist | From 5.0.0-RC1 | 5.9.0-beta.1 | Products: Craftcms Craft Cms. ## How do I fix CVE-2026-28781? Upgrade craftcms/cms to a fixed version for your release line: 4.17.0-beta.1 or 5.9.0-beta.1. ## Is CVE-2026-28781 being exploited? It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28781 exists. ## Other vulnerabilities in Craftcms Craft Cms - [CVE-2025-32432](https://insights.sbomify.com/CVE-2025-32432/): Craft CMS Code Injection (critical 10.0, exploited in the wild) - [CVE-2024-56145](https://insights.sbomify.com/CVE-2024-56145/): Craft CMS Code Injection (critical 9.3, exploited in the wild) - [CVE-2025-23209](https://insights.sbomify.com/CVE-2025-23209/): Craft CMS Code Injection (high 8.1, exploited in the wild) - [CVE-2025-35939](https://insights.sbomify.com/CVE-2025-35939/): Craft CMS External Control of Assumed-Immutable Web Parameter (medium 6.9, exploited in the wild) - [CVE-2023-41892](https://insights.sbomify.com/CVE-2023-41892/): Craft CMS Remote Code Execution vulnerability (critical 10.0) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2026-28781 and fix it if it is affected. What it is: CVE-2026-28781 is a high-severity vulnerability in Craftcms Craft Cms, published on 4 Mar 2026. Any signed-in user can exploit it over the network, with no action from the victim. Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-28781 exists. Affected packages and fixed versions: - craftcms/cms (Packagist): affected from 4.0.0-RC1; fixed in 4.17.0-beta.1 - craftcms/cms (Packagist): affected from 4.0.0-RC1; fixed in 4.17.0-beta.1 - craftcms/cms (Packagist): affected from 5.0.0-RC1; fixed in 5.9.0-beta.1 - craftcms/cms (Packagist): affected from 5.0.0-RC1; fixed in 5.9.0-beta.1 Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2026-28781/ (Markdown: https://insights.sbomify.com/CVE-2026-28781/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2026-28781 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-28781 - OSV: https://osv.dev/vulnerability/CVE-2026-28781 --- From sbomify Insights: https://insights.sbomify.com/CVE-2026-28781/ Summaries are generated and may contain mistakes; the official description above is the record.