CVE-2026-20282

Cisco Identity Services Engine Authenticated Write Vulnerability

No known exploitation. EPSS puts it in the 49th percentile. No fix published yet.

CVSS 3.14.9Medium EPSS percentile49th0.6% chance in 30 days CISA KEVNot listedNo confirmed exploitation
No public exploit known FixNone yetNo fix or workaround published

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OpenVAS · 1 check

e.g. OID 1.3.6.1.4.1.25623.1.0.157975

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Published 2026-09-16Updated 2026-09-22Sources: CVE.org, NVD

NVD CVE.org

What to do

No fixed build or workaround is published yet. Limit exposure and watch for a patch.

Cisco Identity Services Engine SoftwareAffected: 3.1.0Upgrade to: not statedAffected: 3.1.0 p1Upgrade to: not statedAffected: 3.1.0 p3Upgrade to: not statedAffected: 3.1.0 p2Upgrade to: not stated + 45 more branchesStated by: CVE record

Versions as the sources state them. Full version matrix after sign-in

Steps

Written by AI from the record

Check whether you run cisco identity services engine software and identify every account with administrative access.
There is no confirmed fixed version or patch information available; ask Cisco or your support provider for the remediation release and apply it as soon as provided.
Restrict administrative access to trusted staff and management networks, rotate administrator passwords, and remove unused administrator accounts.
Review administrator activity and system changes for unexpected write operations or configuration changes.

May need vendor or contractor work

Check it yourselfA free OpenVAS check exists for this CVE. Run it against your hosts.Is your organisation exposed?Request an assessment to establish which checks fit your systems.

What it is

From the CVE record

A vulnerability in Cisco ISE could allow an authenticated, remote attacker to obtain write access on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to obtain write access to the underlying operating system. To exploit this vulnerability, the attacker must have valid administrative credentials. Note: For CVE-2026-20282, Cisco has assigned a Security Impact Rating (SIR) of High rather than Medium as the score indicates. The reason is that it is easy to get to root from the achieved privilege level.

In plain language

Written by AI from the record

This affects cisco identity services engine software and lets a logged-in administrator change the device’s underlying system; treat it as urgent because a public exploit is available.

Authenticated remote OS write vulnerability in cisco identity services engine software caused by insufficient validation of crafted HTTP-request input; administrative credentials are required.

If you're affected

Device system takeover
Security policy tampering
Network access disruption
Sensitive configuration exposure

What is it

This is a flaw that can let someone who already has an administrator account write files to the system running the device. It is like giving a building manager the ability to alter the building’s wiring behind locked utility doors, rather than only manage normal office settings.

Who is affected

This matters to you if you use or run cisco identity services engine software. It requires an attacker to already have valid administrative credentials, so protecting and limiting those accounts is essential.

How urgent is it

A public exploit is available, and an attacker with an administrator account can alter the underlying system. Treat this as a red-priority issue: immediately limit administrative access and investigate unexpected administrator activity while awaiting Cisco’s patch guidance.

What to do — in detail

Confirm the deployed cisco identity services engine software versions and inventory all administrative accounts, including service and remote-management accounts. The vulnerability is reachable through a crafted HTTP request, but exploitation requires valid administrative credentials; restrict management interfaces to dedicated trusted networks and remove unnecessary administrator access.

No fixed version, supported-version guidance, or vendor workaround is available in the findings. Do not assume an upgrade target; obtain the remediation release and upgrade path directly from Cisco or your support provider before making version changes. If patching is delayed, enforce least privilege for administrator accounts, require strong authentication, rotate credentials where exposure is suspected, and isolate management access from untrusted networks.

There is no CISA KEV due date because this CVE is not listed in the CISA Known Exploited Vulnerabilities catalog. Monitor administrator logins, HTTP requests to management interfaces, unexpected operating-system file changes, configuration changes, and newly created or modified privileged accounts.

Technical context

CVSS v3.1 is 4.9 (Medium): AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N. The weakness is CWE-641, with insufficient validation of user-supplied input enabling an authenticated remote attacker to obtain underlying-OS write access through crafted HTTP requests. A public exploit is available, but the CVE is not listed in CISA KEV. EPSS is 0.6% (45th percentile) and flat; this is a prediction, not confirmation of exploitation. Cisco assigned a High Security Impact Rating because root access is reportedly easy to obtain from the achieved privilege level.

This is a general assessment based on public vulnerability data. It does not account for your specific infrastructure — when in doubt, consult a security specialist.

Exploitation

Where each signal puts this CVE on the scale from published to confirmed exploited.

EPSS49th

CISA KEV

Not in the catalog. CISA has not confirmed exploitation.

Public exploits

No public exploit or proof of concept found in the sources we track.

EPSS

0.6% chance of exploitation activity in the next 30 days, which ranks it in the 49th percentile of scored CVEs.

Exploit Prediction Scoring System, FIRST.org. A probability, not a confirmation.

Lifecycle

6 events over 36 days, from the signal feeds we watch.

2026-10-22OpenVAS check added
2026-09-22Record updated
2026-09-18Record updated
2026-09-16Publishedweakness classified, record updated

Affected products

Ciscocommercial · USaka cisco systems, cisco systems inc.
- Cisco Identity Services Engine SoftwareNetworking Infrastructure

Technical detail

CVSS 3.1 vector

Open in the CVSS calculator

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

Scored 4.9 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 HighRequires admin or elevated privileges
User Interaction NoneNo user interaction needed — fully automated exploitation

Scope

Scope UnchangedImpact is limited to the vulnerable component itself

Impact if exploited

Confidentiality NoneNo confidentiality impact
Integrity HighTotal loss of integrity — attacker can modify any data in the component
Availability NoneNo availability impact