# CVE-2023-25135: Deserialization in n/a

> Unauthenticated attackers can execute arbitrary code on vBulletin forums via crafted HTTP requests exploiting unsafe deserialization.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 3 Feb 2023
- **Updated:** 26 Mar 2025
- **Also known as:** GHSA-r8jw-f89q-p7g6

## What is CVE-2023-25135?

CVE-2023-25135 is a critical unsafe deserialization vulnerability in Vbulletin Vbulletin, published on 3 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

vBulletin before 5.6.9 PL1 allows an unauthenticated remote attacker to execute arbitrary code via a crafted HTTP request that triggers deserialization. This occurs because verify_serialized checks that a value is serialized by calling unserialize and then checking for errors. The fixed versions are 5.6.7 PL1, 5.6.8 PL1, and 5.6.9 PL1.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2023-25135?

It affects 1 product.


Products: Vbulletin Vbulletin.

## How do I fix CVE-2023-25135?

No fix has been published for CVE-2023-25135 yet. Limit exposure of the affected software until one is available.

## Is CVE-2023-25135 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-25135 exists.

Public exploit code:

- vBulletin <= 5.6.9 - Pre-authentication Remote Code Execution (nuclei): http/cves/2023/CVE-2023-25135.yaml

## Other vulnerabilities in Vbulletin Vbulletin

- [CVE-2020-17496](https://insights.sbomify.com/CVE-2020-17496/): vBulletin PHP Module Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2019-16759](https://insights.sbomify.com/CVE-2019-16759/): vBulletin PHP Module Remote Code Execution (critical 9.8, exploited in the wild)
- [CVE-2025-48827](https://insights.sbomify.com/CVE-2025-48827/): vBulletin 5.0.0 through 5.7.5 and 6.0.0 through 6.0.3 allows unauthenticated users to invoke protected API controllers' methods when running (critical 10.0)
- [CVE-2020-7373](https://insights.sbomify.com/CVE-2020-7373/): Code injection in n/a (critical 9.8)
- [CVE-2020-12720](https://insights.sbomify.com/CVE-2020-12720/): SQL injection in n/a (critical 9.8)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2023-25135 and fix it if it is affected.

What it is: CVE-2023-25135 is a critical unsafe deserialization vulnerability in Vbulletin Vbulletin, published on 3 Feb 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-25135 exists.

Affected product: Vbulletin Vbulletin. 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-2023-25135/ (Markdown: https://insights.sbomify.com/CVE-2023-25135/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2023-25135
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2023-25135
- OSV: https://osv.dev/vulnerability/CVE-2023-25135

---
From sbomify Insights: https://insights.sbomify.com/CVE-2023-25135/
Summaries are generated and may contain mistakes; the official description above is the record.