# CVE-2026-50279: Craft CMS: Authorship spoofing in `entries/save-entry` via pre-check/post-mutation authorization gap

> Low-privileged users can spoof entry authorship in Craft CMS by exploiting an authorization gap during entry saving, bypassing peer-author-change permissions.

- **Severity:** High 7.6 (`CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/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:** 1 Jul 2026
- **Updated:** 2 Jul 2026
- **Also known as:** GHSA-qq2c-2q8j-jh27

## What is CVE-2026-50279?

CVE-2026-50279 is a high-severity missing authorization vulnerability in craftcms cms, published on 1 Jul 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Craft CMS is a content management system (CMS). IN versions 5.0.0-RC1 and above prior to 5.9.21, theEntriesController::actionSaveEntry() performs entry-edit permission checks before request-controlled author changes are applied to the model, allowing for authorship spoofing. The subsequent author mutation path accepts attacker-supplied authors / author parameters and allows the change when the current user is one of the old authors. Because the controller does not re-run authorization after mutating the author list, a low-privileged user can reassign an entry’s authorship to another user without holding the dedicated peer-author-change permission. This issue has been fixed in version 5.9.21.

Weakness: CWE-285 (Improper Authorization)

## Which versions are affected by CVE-2026-50279?

2 open source packages ship an affected version, including craftcms/cms.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `craftcms/cms` | Packagist | From 5.0.0-RC1 | 5.9.21 |
| `craftcms/cms` | Packagist | From 5.0.0-RC1 | 5.9.21 |

## How do I fix CVE-2026-50279?

Upgrade craftcms/cms to 5.9.21 or later.

## Is CVE-2026-50279 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-50279 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-50279 and fix it if it is affected.

What it is: CVE-2026-50279 is a high-severity missing authorization vulnerability in craftcms cms, published on 1 Jul 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-2026-50279 exists.

Affected packages and fixed versions:
- craftcms/cms (Packagist): affected from 5.0.0-RC1; fixed in 5.9.21
- craftcms/cms (Packagist): affected from 5.0.0-RC1; fixed in 5.9.21

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-2026-50279/ (Markdown: https://insights.sbomify.com/CVE-2026-50279/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-50279
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-50279
- OSV: https://osv.dev/vulnerability/CVE-2026-50279

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-50279/
Summaries are generated and may contain mistakes; the official description above is the record.