CVE-2025-20124
Cisco Identity Services Engine Java Deserialization Vulnerability
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- Low
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
Cisco Identity Services Engine Java Deserialization Vulnerability
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.
- Record
CVE-2025-20124- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
EUVDEUVD-2025-2152
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.
- Record
EUVD-2025-2152- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-4ch8-9r52-j78v
A vulnerability in an API of Cisco ISE could allow an authenticated, remote attacker to execute...
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.
- Record
GHSA-4ch8-9r52-j78v- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
NVD
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.
- Record
CVE-2025-20124- CVSS 3.1
- 9.9 Critical
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:H/A:H - CVSS 3.1
- 7.2 High
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-502
- Updated
- 2026-11-02
Affected products
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| Exploit-DB | Cisco ISE 3.0 - Remote Code Execution (RCE) | 2025-08-11 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, Exploit-DB, GitHub Advisories, NVD |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2025-20124 is a critical vulnerability (CVSS 9.9) in Cisco Identity Services Engine, published February 5, 2025. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 18.5%, the 97th percentile. No source names a fixed version.