CVE-2026-20307

CVE CVE-2026-20307EUVD EUVD-2026-80886Published 2026-09-16T16:55:55.000ZLast changed 2026-09-17T11:39:24.000ZCVSS 9.9

What the advisory describes

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.

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

Cisco — Cisco Identity Services Engine Software 3.4 Patch 3; 3.4.0; 3.1.0 p7; 3.2 Patch 9; 3.4 Patch 4; 3.3 Patch 1; 3.3 Patch 9; 3.1.0 p72; 3.3 Patch 5; 3.5 Patch 1; 3.1.0 p8; 3.3 Patch 8; 3.2.0 p7; 3.3 Patch 3; 3.4 Patch 2; 3.3 Patch 2; 3.1.0 p2; 3.3 Patch 6; 3.2.0 p1; 3.3 Patch 4; 3.2 Patch 10; 3.2.0 p6; 3.3 Patch 11; 3.1.0 p11; 3.3 Patch 10; 3.1.0 p10; 3.2.0; 3.2.0 p3; 3.2.0 p2; 3.2.0 p4; 3.1.0 p6; 3.4 Patch 6; 3.1.0 p4; 3.5 Patch 2; 3.5 Patch 3; 3.1.0 p9; 3.3.0; 3.1.0 p1; 3.4 Patch 5; 3.2 Patch 8; 3.1.0 p5; 3.5.0; 3.2.0 p5; 3.1.0; 3.1.0 p3; 3.4 Patch 1; 3.3 Patch 7

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

Cisco — Identity Services Engine Software

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