CVE-2026-20307Cisco Identity Services Engine Remote Code Execution Vulnerability
- 9.9CriticalCVSS base score
- 0.98%Exploitation in 30 daysEPSS · top 37% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
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.
Timeline
ID reserved
By cisco
- 11 months later
· 11 months later
Published
- 1 day later
· 1 day later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| ciscoCNA (assigner) | 3.1 | Critical9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Awaiting Analysis | 3.1 | Critical9.9 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.98% · top 37% of all CVEs (12 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.9.
Affected products
Cisco · Cisco Identity Services Engine Software
- affected 3.1.0
- affected 3.1.0 p1
- affected 3.1.0 p3
- affected 3.1.0 p2
- affected 3.2.0
- affected 3.1.0 p4
- affected 3.1.0 p5
- affected 3.2.0 p1
- affected 3.1.0 p6
- affected 3.2.0 p2
- affected 3.1.0 p7
- affected 3.3.0
- affected 3.2.0 p3
- affected 3.2.0 p4
- affected 3.1.0 p8
- affected 3.2.0 p5
- affected 3.2.0 p6
- affected 3.1.0 p9
- affected 3.3 Patch 2
- affected 3.3 Patch 1
- affected 3.3 Patch 3
- affected 3.4.0
- affected 3.2.0 p7
- affected 3.3 Patch 4
- affected 3.4 Patch 1
- affected 3.1.0 p10
- affected 3.3 Patch 5
- affected 3.3 Patch 6
- affected 3.4 Patch 2
- affected 3.3 Patch 7
- affected 3.4 Patch 3
- affected 3.5.0
- affected 3.4 Patch 4
- affected 3.3 Patch 8
- affected 3.2 Patch 8
- affected 3.5 Patch 1
- affected 3.3 Patch 9
- affected 3.2 Patch 9
- affected 3.4 Patch 5
- affected 3.5 Patch 3
- and 7 more
What to do
Exploitation: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.
References
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-80886 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-20307)Record last updated .