CVE Watchtower

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CVE-2026-20307NVD

Vulnerability Summary

A vulnerability in the web-based management interface of 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 at least low-privileged administrative credentials.

This vulnerability is due to insecure deserialization of a user-supplied Java byte stream. An attacker could exploit this vulnerability by sending a crafted serialized Java object to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the device and 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 denial of service (DoS) condition. In that condition, endpoints that have not already authenticated would be unable to access the network until the node is restored.
Severity Level
CRITICAL(9.9)
Published Date
Sep 16, 2026
Last Modified
Sep 17, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.96%Probability
Root Weakness (CWE)
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.
CVSS v3.1 Base Metrics — Score 9.9 (CRITICAL)
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredLow
User InteractionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

Affected & Patched Versions

Affected Versions
  • Cisco Cisco Identity Services Engine Software >= 3.1.0
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p1
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p3
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p2
  • Cisco Cisco Identity Services Engine Software >= 3.2.0
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p4
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p5
  • Cisco Cisco Identity Services Engine Software >= 3.2.0 p1
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p6
  • Cisco Cisco Identity Services Engine Software >= 3.2.0 p2
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p7
  • Cisco Cisco Identity Services Engine Software >= 3.3.0
  • Cisco Cisco Identity Services Engine Software >= 3.2.0 p3
  • Cisco Cisco Identity Services Engine Software >= 3.2.0 p4
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p8
  • Cisco Cisco Identity Services Engine Software >= 3.2.0 p5
  • Cisco Cisco Identity Services Engine Software >= 3.2.0 p6
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p9
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 2
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 1
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 3
  • Cisco Cisco Identity Services Engine Software >= 3.4.0
  • Cisco Cisco Identity Services Engine Software >= 3.2.0 p7
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 4
  • Cisco Cisco Identity Services Engine Software >= 3.4 Patch 1
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p10
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 5
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 6
  • Cisco Cisco Identity Services Engine Software >= 3.4 Patch 2
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 7
  • Cisco Cisco Identity Services Engine Software >= 3.4 Patch 3
  • Cisco Cisco Identity Services Engine Software >= 3.5.0
  • Cisco Cisco Identity Services Engine Software >= 3.4 Patch 4
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 8
  • Cisco Cisco Identity Services Engine Software >= 3.2 Patch 8
  • Cisco Cisco Identity Services Engine Software >= 3.5 Patch 1
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 9
  • Cisco Cisco Identity Services Engine Software >= 3.2 Patch 9
  • Cisco Cisco Identity Services Engine Software >= 3.4 Patch 5
  • Cisco Cisco Identity Services Engine Software >= 3.5 Patch 3
  • Cisco Cisco Identity Services Engine Software >= 3.5 Patch 2
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 10
  • Cisco Cisco Identity Services Engine Software >= 3.3 Patch 11
  • Cisco Cisco Identity Services Engine Software >= 3.4 Patch 6
  • Cisco Cisco Identity Services Engine Software >= 3.2 Patch 10
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p72
  • Cisco Cisco Identity Services Engine Software >= 3.1.0 p11
Patched Versions
Not provided by cveorg for this CVE.
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🚫Ad-Free — Uninterrupted experience.
🎁7-Day Free Trial — Try Pro or Team, no card required.
📧Email Delivery — Threat intel straight to your inbox.
♾️Unlimited Vendors — Track your entire stack.
🚨All New CVEs — Be the first to know.
📈EPSS Spike Alerts — Catch rising risk before it peaks.
🎯Custom EPSS/CVSS — Filter noise, focus on risk.
🛡️Exploit Intel — A 2nd confirmed-exploit signal beyond KEV.
🐙GitHub Issues — Auto-tracked, no duplicates.
📬Weekly Digest — One clean summary, not inbox spam.
🏷️Watchlist Groups — Tag alerts by team (Infra/AppSec/SOC).
💬Webhooks — Slack & Teams integration.
🔀Smart Routing — Critical alerts to one channel, rest to another.
🚫Ad-Free — Uninterrupted experience.