# CVE-2026-95806: MISP: PHP phar stream wrapper enables deserialization and code execution via caller-influenced filesystem paths

> Attackers can achieve arbitrary code execution by exploiting the PHP phar stream wrapper to trigger deserialization via manipulated filesystem paths.

- **Severity:** High 7.7 (`CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/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:** No
- **Published:** 22 Sep 2026
- **Updated:** 22 Sep 2026
- **Also known as:** GHSA-8rgx-3gvf-26gg

## What is CVE-2026-95806?

CVE-2026-95806 is a high-severity unsafe deserialization vulnerability in MISP, published on 22 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

MISP ships with PHP's phar stream wrapper registered in both its web entry point and its console entry point. 

The phar stream wrapper causes PHP to treat a phar archive as a directory, which has two security consequences:  

 - any filesystem operation on a caller-influenced path that resolves to a phar archive triggers an implicit unserialize() call, creating a deserialization sink;
 - a relocated application root can reach executable code inside an uploaded phar file, enabling arbitrary code execution as the web user.

No component of MISP, the vendored CakePHP framework, or any runtime-loaded library reads or constructs phar archives. The wrapper therefore serves no legitimate purpose in the MISP runtime and exists solely as an available primitive for an attacker who can influence a filesystem path argument.

Weakness: CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component), CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2026-95806?


## How do I fix CVE-2026-95806?

No fix has been published for CVE-2026-95806 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-95806 being exploited?

There is no known exploitation of CVE-2026-95806 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-95806 and fix it if it is affected.

What it is: CVE-2026-95806 is a high-severity unsafe deserialization vulnerability in MISP, published on 22 Sep 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-2026-95806 in the wild and no public exploit code.

Affected product: MISP. 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-2026-95806/ (Markdown: https://insights.sbomify.com/CVE-2026-95806/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-95806
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-95806
- OSV: https://osv.dev/vulnerability/CVE-2026-95806

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-95806/
Summaries are generated and may contain mistakes; the official description above is the record.