Security Digest · Vulnerability record · Known exploited

CVE-2025-20281: Cisco Identity Services Engine Injection Vulnerability

Exploited in the wild (CISA KEV). A vulnerability in a specific API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to execute arbitrary code on the underlying operating system as root.

CISA KEV · added 2025-07-28 CVSS 10.0 Critical EPSS 97.6% · p99.9

Should you act?

Exploited: patch now if you run it

CISA has confirmed exploitation in the wild. This signal is computed from CISA KEV, EPSS and CVSS data; it is not an editorial verdict.

  • Yes, if you run Cisco Identity Services Engine. CISA added this CVE to its Known Exploited Vulnerabilities catalog on 2025-07-28, which means there is reliable evidence of exploitation in the wild. US federal agencies must remediate by 2025-08-18; treat that as the outer limit, not the target.
  • EPSS 97.6%, percentile 99.9: FIRST’s model estimates a 97.6% chance of exploitation activity in the next 30 days, higher than 99.9% of all scored CVEs (very high). EPSS is a probability, not a verdict.
  • Remotely reachable with no login and no user interaction. If the vulnerable service is exposed to the internet, prioritize it.

What it is

A vulnerability in a specific API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to execute arbitrary code on the underlying operating system as root. The attacker does not require any valid credentials to exploit this vulnerability. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by submitting a crafted API request. A successful exploit could allow the attacker to obtain root privileges on an affected device.

CISA’s summary

Cisco Identity Services Engine contains an injection vulnerability in a specific API of Cisco ISE and Cisco ISE-PIC due to insufficient validation of user-supplied input allowing an attacker to exploit this vulnerability by submitting a crafted API request. Successful exploitation could allow an attacker to perform remote code execution and obtaining root privileges on an affected device.

Weakness type: CWE-74.

Product: Cisco Identity Services Engine · Assigned by: cisco · Published: 2025-06-25

Affected and fixed versions

VendorProductAffected versions (per CVE record)
CiscoCisco Identity Services Engine Software3.3.0, 3.3 Patch 2, 3.3 Patch 1, 3.3 Patch 3, 3.4.0, 3.3 Patch 4, 3.4 Patch 1, 3.3 Patch 5, 3.3 Patch 6

Severity scores

Scored byCVSSScoreVector
cisco3.110 CriticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
  • Attack vector: network (remotely reachable)
  • Attack complexity: low
  • Privileges required: none (no login)
  • User interaction: none
  • Scope: changed (can affect other components)

CVSS measures how bad a flaw is if exploited, not how likely exploitation is. Read it next to the exploitation data below.

Exploitation and urgency

  • CISA KEV: added 2025-07-28; federal due date 2025-08-18. Known ransomware use: Unknown.
  • CISA required action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
  • CISA SSVC assessment: exploitation active, automatable yes, technical impact total.
  • FIRST EPSS (model of 2026-10-21): 97.60% probability of exploitation activity in the next 30 days; percentile 99.9.

Timeline

  • — CVE record published by cisco
  • — Added to CISA’s Known Exploited Vulnerabilities catalog
  • — CISA remediation deadline for US federal agencies
  • — CVE record last updated

Sources and references

Original sources first. Version and fix details should always be confirmed against the vendor or project advisory.

Vendor and project advisories, patches

  1. Listed in CISA KEV notes (sec.cloudapps.cisco.com) sec.cloudapps.cisco.com

Vulnerability records

  1. CVE.org record CVE-2025-20281 cve.org
  2. NVD entry CVE-2025-20281 nvd.nist.gov

Government

  1. CISA Known Exploited Vulnerabilities catalog entry cisa.gov

Other references from the CVE record and advisory

  1. zerodayinitiative.com zerodayinitiative.com

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