Exploited CVEs / Cisco / CVE-2023-20198

CVE-2023-20198

Cisco IOS XE Web UI Privilege Escalation Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2023-10-20 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Cisco Security Advisories (PSIRT), linked below.

Risk summary

CriticalCISA KEV

10.0

CVSS v3 base

100%

EPSS exploit probability

Critical

Severity

2023-10-16

Added to KEV

2023-10-20 (past due)

CISA due date

Actively exploited Cisco IOS XE Web UI vulnerability, Critical severity, CVSS v3 10.0. Added to the CISA KEV catalog 2023-10-16.

Senserva AI read on CVE-2023-20198 CISA required action Official fix for CVE-2023-20198 Admin questions

Senserva AI Opinion for CVE-2023-20198

A perfect CVSS 10.0 and a 100% EPSS score: this Cisco IOS XE web UI flaw lets a remote, unauthenticated attacker create a privilege level 15 account and take full control of the device. Mass exploitation compromised internet-exposed IOS XE devices at scale after its October 2023 KEV listing, usually followed by the companion command injection to plant an implant. If a router or switch had its web UI reachable from the internet, assume it was probed.

Do this: Disable the IOS XE web UI on untrusted interfaces, patch, and check the local user database for accounts you did not create.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2023-20198

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2023-20198, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2023-20198.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2023-20198: Cisco IOS XE Web UI Privilege Escalation Vulnerability
- Affected: Cisco IOS XE Web UI
- Severity: Critical, CVSS v3 10.0; EPSS 30-day exploitation probability 100%
- Added to CISA KEV: 2023-10-16; federal remediation due 2023-10-20
- Ransomware-linked: no
- CISA required action: Verify that instances of Cisco IOS XE Web UI are in compliance with BOD 23-02 and apply mitigations per vendor instructions. For affected products (Cisco IOS XE Web UI exposed to the internet or to untrusted networks), follow vendor instructions to determine if a system may have been compromised ...
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

The fix ships from the vendor: Cisco Security Advisories (PSIRT).

Do this now: Federal remediation deadline 2023-10-20; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 29, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2023-20198

Published: 2023-10-16
Last revised: 2023-10-16
Changes tracked: 1

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

2023-10-16 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 10.0; EPSS first scored at 99.6%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2023-10-20 (past due).

Verify that instances of Cisco IOS XE Web UI are in compliance with BOD 23-02 and apply mitigations per vendor instructions. For affected products (Cisco IOS XE Web UI exposed to the internet or to untrusted networks), follow vendor instructions to determine if a system may have been compromised and immediately report positive findings to CISA.

Official fix for CVE-2023-20198

The authoritative fix and affected-version list are published by the vendor. Find the IOS XE Web UI advisory on Cisco Security Advisories (PSIRT).

Cisco Security Advisories (PSIRT)CISA KEV entry

Common questions about CVE-2023-20198

Is CVE-2023-20198 actively exploited?

Yes. CVE-2023-20198 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2023-10-16, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 100%.

What is the CISA deadline and required action for CVE-2023-20198?

CISA set the federal (BOD 22-01) remediation due date at 2023-10-20, which has passed; treat any unremediated system as overdue. The verbatim required action: Verify that instances of Cisco IOS XE Web UI are in compliance with BOD 23-02 and apply mitigations per vendor instructions. For affected products (Cisco IOS XE Web UI exposed to the internet or to untrusted networks), follow vendor instructions to determine if a system may have been compromised and immediately report positive findings to CISA.

What fixes CVE-2023-20198?

The authoritative fix is in the vendor advisory: see Cisco Security Advisories (PSIRT) for the patched IOS XE Web UI versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2023-20198?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2023-20198's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

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All Cisco exploited CVEs on one page: Cisco vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.