How severe is CVE-2026-21671?

CVE-2026-21671 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-21671 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-21671?

CVE-2026-21671 affects Veeam Veeam Backup & Replication. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-21671?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2026-21671 have an EU (EUVD) identifier?

Yes. CVE-2026-21671 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11583.

When was CVE-2026-21671 published?

CVE-2026-21671 was published on 2026-03-12 and last updated on 2026-06-17.

CVE-2026-21671

CVE-2026-21671 is a critical-severity vulnerability in Veeam Veeam Backup & Replication with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-94.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-11583
Weakness: CWE-94
Affected product: Veeam Veeam Backup & Replication
Published: 2026-03-12
Last modified: 2026-06-17

Description

A vulnerability allowing an authenticated user with the Backup Administrator role to perform remote code execution (RCE) in high availability (HA) deployments of Veeam Backup & Replication.

Frequently asked questions

What is CVE-2026-21671?: A vulnerability allowing an authenticated user with the Backup Administrator role to perform remote code execution (RCE) in high availability (HA) deployments of Veeam Backup & Replication.
How severe is CVE-2026-21671?: CVE-2026-21671 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-21671 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-21671?: CVE-2026-21671 affects Veeam Veeam Backup & Replication. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-21671?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2026-21671 have an EU (EUVD) identifier?: Yes. CVE-2026-21671 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11583.
When was CVE-2026-21671 published?: CVE-2026-21671 was published on 2026-03-12 and last updated on 2026-06-17.

References

https://www.veeam.com/kb4831

Affected products (1)

cpe:2.3:a:veeam:veeam_backup_\&_replication:*:*:*:*:*:*:*:*

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