CVE-2026-20307
Cisco Identity Services Engine Remote Code Execution Vulnerability
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.
In plain language
AI Act nowCisco Identity Services Engine Software has a critical flaw that can let a low-level administrator take over the system; businesses using it should act urgently.
Authenticated remote code execution through insecure Java deserialization in the Cisco ISE web management interface allows a low-privileged administrator to execute commands as root.
What to do now
- Check whether your business runs Cisco Identity Services Engine Software and identify everyone with administrator access to its web management interface.
- Ask Cisco or your support provider for the fixed release for CVE-2026-20307; no patch or fixed version information is currently available.
- Until Cisco provides a fix, limit the management interface to a separate admin network and remove unneeded low-level administrator accounts.
- Review administrator logins and system command activity for unexpected changes, then rotate administrator passwords if anything looks suspicious.
CVSS Vector Breakdown
AV:NAttack VectorAC:LAttack ComplexityPR:LPrivileges RequiredUI:NUser InteractionS:CScopeC:HConfidentialityI:HIntegrityA:HAvailabilityWeaknesses
Affected Products
Exploitability
Exploit details including PoC links, Metasploit modules, and scanner templates are available after registration.
View exploit detailsAttack Graph
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MITRE ATT&CK
3 techniquesReferences
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