# CVE-2025-20124: Cisco Identity Services Engine Java Deserialization Vulnerability

> Authenticated attackers with read-only admin credentials can execute arbitrary commands as root via insecure Java deserialization in Cisco ISE.

- **Severity:** Critical 9.9 (`CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H`)
- **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 Feb 2025
- **Updated:** 26 Feb 2026
- **Also known as:** GHSA-4ch8-9r52-j78v

## What is CVE-2025-20124?

CVE-2025-20124 is a critical unsafe deserialization vulnerability in Cisco Identity Services Engine, published on 5 Feb 2025. Any signed-in user can exploit it over the network, with no action from the victim.

### Official description

A vulnerability in an API of Cisco ISE could allow an authenticated, remote attacker to execute arbitrary commands as the root user on an affected device.

This vulnerability is due to insecure deserialization of user-supplied Java byte streams by the affected software. An attacker could exploit this vulnerability by sending a crafted serialized Java object to an affected API. A successful exploit could allow the attacker to execute arbitrary commands on the device and elevate privileges.
Note: To successfully exploit this vulnerability, the attacker must have valid read-only administrative credentials. In a single-node deployment, new devices will not be able to authenticate during the reload time.

Weakness: CWE-502 (Deserialization of Untrusted Data)

## Which versions are affected by CVE-2025-20124?

It affects 1 product.


Products: Cisco Identity Services Engine.

## How do I fix CVE-2025-20124?

No fix has been published for CVE-2025-20124 yet. Limit exposure of the affected software until one is available.

## Is CVE-2025-20124 being exploited?

There is no known exploitation of CVE-2025-20124 in the wild and no public exploit code.

Public exploit code:

- Cisco ISE 3.0 - Remote Code Execution (RCE) (exploitdb)

## Other vulnerabilities in Cisco Identity Services Engine

- [CVE-2026-76460](https://insights.sbomify.com/CVE-2026-76460/): Cisco Identity Services Engine Incorrect Use of Privileged APIs (critical 10.0, exploited in the wild)
- [CVE-2025-20337](https://insights.sbomify.com/CVE-2025-20337/): Cisco Identity Services Engine Injection (critical 10.0, exploited in the wild)
- [CVE-2025-20281](https://insights.sbomify.com/CVE-2025-20281/): Cisco Identity Services Engine Injection (critical 10.0, exploited in the wild)
- [CVE-2026-20130](https://insights.sbomify.com/CVE-2026-20130/): Cisco Identity Services Engine Hardening Release - Improper Neutralization Vulnerabilities (critical 10.0)
- [CVE-2026-20192](https://insights.sbomify.com/CVE-2026-20192/): Cisco Identity Services Engine Hardening Release - Access Control Vulnerabilities (critical 10.0)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-20124 and fix it if it is affected.

What it is: CVE-2025-20124 is a critical unsafe deserialization vulnerability in Cisco Identity Services Engine, published on 5 Feb 2025. Any signed-in user can exploit it over the network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-20124 in the wild and no public exploit code.

Affected product: Cisco Identity Services Engine. 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-2025-20124/ (Markdown: https://insights.sbomify.com/CVE-2025-20124/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-20124
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-20124
- OSV: https://osv.dev/vulnerability/CVE-2025-20124

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-20124/
Summaries are generated and may contain mistakes; the official description above is the record.