CVE-2026-20211

criticalpriority · track · 36EPSS 0.008 · 58 %ileNLUS
grimoire priorityP2 · Scheduled
Exploitable?
—
no known exploitation
Likely / severe?
0.84% (58th) EPSS
CVSS 9.1 · critical
Is it mine?
49 products
Check your exposure
Who says so?
3 sources
cisco_csaf · ncsc_nl · zdi

EPSS · scored 2026-10-27

A vulnerability in Cisco ISE could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. To exploit this vulnerability, the attacker must have valid high-privileged administrative credentials. This vulnerability is due to insecure deserialization of Java objects by the affected software. An attacker could exploit this vulnerability by sending a crafted serialized Java object to an affected device. A successful exploit could allow the attacker to obtain user-level access to the underlying operating system and then elevate privileges to root. In single-node deployments, successful exploitation of this vulnerability could cause the affected ISE node to become unavailable, resulting in a DoS condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored.

01

remediations

Vendor fix, mitigation, or workaround guidance, as published by each source.

A vendor fix is available.

02

cvss

Technical severity, 0–10. One row per scoring source.

9.1
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 8.3–9.1

v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:Hprimary · psirt@cisco.com USexploitability 2.3 · impact 6
v3.18.3highCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:Hsecondary · NCSC-NL NL
v3.19.1criticalCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:Hsecondary · Cisco PSIRT US
03

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: no · Technical Impact: totalcoordinatorcisa_ssvcUS
04

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-502USCWE-502US
05

affected products (49)

Products and version ranges known to be affected.

showing 20 of 49
06

advisories (3)

Vendor and ecosystem advisories describing this.

  • NCSC-2026-0382Kwetsbaarheden verholpen in Cisco Identity Services Engine (ISE)NL2026-09-17csaf · ncsc_nlNL

    Cisco heeft 21 kwetsbaarheden verholpen in Cisco Identity Services Engine (ISE) en Cisco ISE Passive Identity Connector (ISE-PIC).

  • cisco-sa-ise-rce-se7bYU57Cisco Identity Services Engine Remote Code Execution Vulnerabilities2026-09-16csaf · cisco_csafUS

    Multiple vulnerabilities in Cisco Identity Services Engine (ISE) could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. To exploit these vulnerabilities, the attacker must have valid administrative credentials. For more information about these vulnerabilities, see the Details ["#details"] section of this advisory. Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities. This advisory is part of a group of advisories. For a complete list of the advisories and links to them, see Cisco Advance Notification for Publication of September 16, 2026, Security Advisories ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-notice-jfxK98ZP"]. In addition, for further documentation of improvements and fixes in Cisco Identity Services Engine, see Cisco Identity Services Engine Security Hardening Release: September 2026 ["https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-hardening-ise-XU5EwX5T"].

  • ZDI-26-717ZDI advisory ZDI-26-7172026-09-18vendor · zdiUS
07

sources

Which sources assert this record, and when.

cisco_csafncsc_nlzdiNVDCVE.orgMITRE
published 2026-09-16modified 2026-09-17
08

references (1) nvd

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan