CVE-2026-20307
Cisco Identity Services Engine Remote Code Execution Vulnerability
Public exploit available. Not confirmed exploited in the wild yet. No fix published yet.
What to do
No fixed build or workaround is published yet. Limit exposure and watch for a patch.
Steps
Written by AI from the record- 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.
What it is
From the CVE record
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
Written by AI from the recordCisco 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.
If you're affected
- Full identity-system takeover
- Network access disruption
- Unauthorized administrator access
- Service outage
Exploitation
Where each signal puts this CVE on the scale from published to confirmed exploited.
- CISA KEV
Not in the catalog. CISA has not confirmed exploitation.
- Public exploits
0 sources with a proof of concept or module.
Exploit links, PoCs and Metasploit modules after sign-in- EPSS
1.0% chance of exploitation activity in the next 30 days, which ranks it in the 60th percentile of scored CVEs.
Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.
Lifecycle
6 events over 1 day, from the signal feeds we watch.
- Record updatedrecord updated
- Publishedweakness classified, att&ck mapped, record updated
Affected products
Technical detail
CVSS 3.1 vector
Open in the CVSS calculatorCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Scored 9.9 by NVD.
How it is reached
- Attack Vector NetworkExploitable remotely over the network without any special conditions
- Attack Complexity LowNo special conditions — the attack can be reliably reproduced
- Privileges Required LowRequires basic user-level privileges
- User Interaction NoneNo user interaction needed — fully automated exploitation
Scope
- Scope ChangedThe exploit can affect other components (e.g. sandbox escape, host compromise from VM)
Impact if exploited
- Confidentiality HighTotal information disclosure — all data in the component is compromised
- Integrity HighTotal loss of integrity — attacker can modify any data in the component
- Availability HighTotal denial of service — the component is completely unavailable
Weaknesses
ATT&CK techniques
Mapped from the weaknesses above (CWE to ATT&CK), not observed in attacks.
Sources
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