# CVE-2026-58143: Cotonti Siena 0.9.26 CSRF via admin.php Config Update Endpoint

> Attackers can trick admins into disabling file upload restrictions, allowing arbitrary PHP execution via forged requests.

- **Severity:** High 8.7 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** A user has to click or open something
- **Fix available:** No
- **Published:** 9 Jul 2026
- **Updated:** 1 Oct 2026
- **Also known as:** GHSA-v64j-9r6x-4fv6

## What is CVE-2026-58143?

CVE-2026-58143 is a high-severity vulnerability in Cotonti, published on 9 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.

### Official description

Cotonti Siena 0.9.26 and earlier contains a cross-site request forgery vulnerability that allows unauthenticated attackers to modify administrator configuration by tricking a logged-in administrator into submitting a forged POST request to the admin.php config update handler, which never invokes the application's CSRF validation function. Attackers can disable the PFS module's file extension whitelist by setting pfsfilecheck to 0, enabling any user with PFS access to upload and execute arbitrary PHP files on the server.

Weakness: CWE-352 (Cross-Site Request Forgery)

## Which versions are affected by CVE-2026-58143?


## How do I fix CVE-2026-58143?

No fix has been published for CVE-2026-58143 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-58143 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-58143 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-58143 and fix it if it is affected.

What it is: CVE-2026-58143 is a high-severity vulnerability in Cotonti, published on 9 Jul 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-58143 exists.

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-2026-58143/ (Markdown: https://insights.sbomify.com/CVE-2026-58143/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-58143
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-58143
- OSV: https://osv.dev/vulnerability/CVE-2026-58143

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-58143/
Summaries are generated and may contain mistakes; the official description above is the record.