Exploited CVEs / Cisco / CVE-2021-1498

CVE-2021-1498

Cisco HyperFlex HX Data Platform Command Injection Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2021-11-17 (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

9.8

CVSS v3 base

100%

EPSS exploit probability

Critical

Severity

2021-11-03

Added to KEV

2021-11-17 (past due)

CISA due date

Actively exploited Cisco HyperFlex HX vulnerability, Critical severity, CVSS v3 9.8. Added to the CISA KEV catalog 2021-11-03.

Senserva AI read on CVE-2021-1498 CISA required action Official fix for CVE-2021-1498 Admin questions

Senserva AI Opinion for CVE-2021-1498

This is an unauthenticated command injection in the Cisco HyperFlex HX Installer VM that lets attackers run commands as the tomcat8 user via crafted web requests. It carries a Severity of Critical (CVSS 9.8), sits in CISA KEV as confirmed exploited since 2021-11-03, and EPSS rates exploitation at 100 percent, so any internet-reachable installer is a live target. The tomcat8 foothold is often the entry point for pivoting into the storage cluster.

Do this: Identify HyperFlex HX Installer VMs, apply Cisco's patched release now, and take any exposed installer offline until updated.

AI-generated from public data, 2026-07-27. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2021-1498

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

I run IT security. Facts for CVE-2021-1498, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2021-1498.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed once a day (early morning US Central)):
- CVE-2021-1498: Cisco HyperFlex HX Data Platform Command Injection Vulnerability
- Affected: Cisco HyperFlex HX
- Severity: Critical, CVSS v3 9.8; EPSS 30-day exploitation probability 100%
- Added to CISA KEV: 2021-11-03; federal remediation due 2021-11-17
- Ransomware-linked: no
- CISA required action: Apply updates per vendor instructions.
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 2021-11-17; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated September 3, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2021-1498

Published: 2021-11-03
Last revised: 2021-11-03
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

2021-11-03 added to the CISA KEV catalog by CISA
2026-07-17 CVSS 0.0 to 9.8; EPSS first scored at 100.0%

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: 2021-11-17 (past due).

Apply updates per vendor instructions.

Official fix for CVE-2021-1498

The authoritative fix and affected-version list are published by the vendor. Find the HyperFlex HX advisory on Cisco Security Advisories (PSIRT).

Cisco Security Advisories (PSIRT)CISA KEV entry

Common questions about CVE-2021-1498

Is CVE-2021-1498 actively exploited?

Yes. CVE-2021-1498 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2021-11-03, 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-2021-1498?

CISA set the federal (BOD 22-01) remediation due date at 2021-11-17, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.

What fixes CVE-2021-1498?

The authoritative fix is in the vendor advisory: see Cisco Security Advisories (PSIRT) for the patched HyperFlex HX 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-2021-1498?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2021-1498'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 once a day (early morning 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.