Cisco Identity Services Engine Software: Improper Neutralization of Special Elements in Output Used by a Downstream Component
CVE-2026-20130 is a critical-severity improper neutralization of special elements in output used by a downstream component vulnerability in Cisco Identity Services Engine Software from Cisco, with a CVSS 3.1 base score of 10.0 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Cisco Identity Services Engine Software versions: 3.1.0; 3.1.0 p1; 3.1.0 p3, and others listed below. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.54% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Identity Services Engine to 3.3.0 or a later version.
- Update Identity Services Engine Passive Identity Connector to 3.3.0 or a later version.
- Read the advisory on sec.cloudapps.cisco.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Cisco | Cisco Identity Services Engine Software | 3.1.0; 3.1.0 p1; 3.1.0 p3; 3.1.0 p2; 3.2.0; 3.1.0 p4; 3.1.0 p5; 3.2.0 p1; and 32 more ranges | Not stated |
| Cisco | Cisco ISE Passive Identity Connector | 3.2.0; 3.1.0; 3.3.0; 3.4.0; 3.5.0 | Not stated |
| Cisco | Identity Services Engine | 3.1.0 up to, but not including, 3.3.0; 3.3.0; 3.4.0; 3.5.0 | 3.3.0 |
| Cisco | Identity Services Engine Passive Identity Connector | 3.1.0 up to, but not including, 3.3.0; 3.3.0; 3.4.0 | 3.3.0 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- ChangedThe attack can reach beyond the vulnerable component into other systems.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H. Scored by CNA (cisco.com).
Official description
As part of Cisco's ongoing commitment to proactive security and product quality, the Cisco Identity Services Engine (ISE) and Cisco ISE Passive Identity Connector (ISE-PIC), engineering teams have conducted a comprehensive internal security review. This review resulted in a software hardening release that addresses multiple internally discovered vulnerabilities. The vulnerabilities tracked by CVE-2026-20130 are related to improper neutralization of special elements issues that are grouped under the Common Weakness Enumeration (CWE) Pillar CWE-74.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Neutralization of Special Elements in Output Used by a Downstream Component
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.
How developers prevent this class of flaw
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
- Utilize an appropriate mix of allowlist and denylist parsing to filter control-plane syntax from all input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other vulnerabilities in Cisco Identity Services Engine Software
- 10.0 Critical severity
- 7.6 High severity
- 7.2 High severity
- 8.6 High severity
- 7.1 High severity
- 9.1 Critical severity
Recent Improper Neutralization of Special Elements in Output Used by a Downstream Component vulnerabilities
- 7.3 High severity
- 7.3 High severity
- 7.3 High severity
- 8.1 High severity
- 9.8 Critical severity
- 7.3 High severity
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