CVE-2021-26989Network attack vector

Authenticated service interruption via undisclosed SMB flaw

Published Mar 4, 2021 · Updated Aug 3, 2024

Denial of service in NetApp ONTAP before 9.3P21, 9.5P16, 9.6P12, 9.7P9, and 9.8 allows remote authenticated users to interrupt service. The vendor record identifies SMB access as the affected path but does not disclose the request, parser, or operation that triggers the failure. Exploitation requires authenticated SMB access to an SMB-enabled cluster and affects availability; no confidentiality or integrity impact is reported.

CVSS severity6.5
Medium
EPSS probability1.15%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in NetApp ONTAP before 9.3P21, 9.5P16, 9.6P12, 9.7P9, and 9.8 allows remote authenticated users to interrupt service. The vendor record identifies SMB access as the affected path but does not disclose the request, parser, or operation that triggers the failure. Exploitation requires authenticated SMB access to an SMB-enabled cluster and affects availability; no confidentiality or integrity impact is reported.

The record

CVE
CVE-2021-26989
Published
Mar 4, 2021
Updated
Aug 3, 2024
Vendor
NetApp
Product
ONTAP
Classifications
T1499
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 4, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Prior to 9.3P21, 9.5P16, 9.6P12, 9.7P9 and 9.8

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

NetApp · ONTAPversion=Prior to 9.3P21, 9.5P16, 9.6P12, 9.7P9 and 9.8

Published CVSS scores

6.5NVDCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
3.5NVDAV:N/AC:M/Au:S/C:N/I:N/A:P

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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