# CVE-2026-71294: Cotonti CMS Comments Plugin PHP Object Injection via Unrestricted unserialize() in Create/Edit Actions

> Attackers with comment write access can execute arbitrary code via PHP object injection in the Cotonti CMS Comments plugin.

- **Severity:** High 7.7 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Aug 2026
- **Updated:** 10 Aug 2026
- **Also known as:** GHSA-rm37-v7mc-6795

## What is CVE-2026-71294?

CVE-2026-71294 is a high-severity unsafe deserialization vulnerability in Cotonti, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

Cotonti CMS's Comments plugin deserializes user-supplied data without restricting the classes that may be instantiated. In plugins/comments/controllers/actions/CreateAction.php, a POST parameter obtained via (trim-only sanitization) is passed to with no restriction, reachable by any member with write access to comments (the default setting in plugins/comments/comments.setup.php).

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-71294?


## How do I fix CVE-2026-71294?

No fix has been published for CVE-2026-71294 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-71294 being exploited?

There is no known exploitation of CVE-2026-71294 in the wild and no public exploit code.

Public exploit code:

- Safe local proof of concept for the Cotonti CommentsWidget PHP object injection vulnerability (CAN-2026-2035973 / CVE-2026-71294). (github_poc): https://github.com/HarshRajSinghania/cotonti-commentswidget-poc

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-71294 and fix it if it is affected.

What it is: CVE-2026-71294 is a high-severity unsafe deserialization vulnerability in Cotonti, published on 5 Aug 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-71294 in the wild and no public exploit code.

Affected product: Cotonti. No package-level version data is available, so check the vendor advisory linked from the reference page.

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-2026-71294/ (Markdown: https://insights.sbomify.com/CVE-2026-71294/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-71294
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-71294
- OSV: https://osv.dev/vulnerability/CVE-2026-71294

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-71294/
Summaries are generated and may contain mistakes; the official description above is the record.