A vulnerability allowing an authenticated user with the Backup Administrator role to perform remote code execution (RCE) in high availabili…

published 2026-03-12 7mo ago modified 2026-06-17 4mo ago also EUVD-2026-11583

cvss: 9.1; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 1.5%; EPSS 1.5% chance of exploitation in 30 days, percentile 73%
public exploits: 0; none known

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.

Is CVE-2026-21671 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

Check with Fencer

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: total
Assessed: 7mo ago (2026-03-13)

Exploit prediction

1.46% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.1	9.1	CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Affected products

Veeam Software Appliance

Classification

Weakness

CWE-693 Protection Mechanism Failure
CWE-94 Improper Control of Generation of Code

References

veeam.com /kb4831
vendor-advisory

Sources

CVE List CVE-2026-21671
NVD CVE-2026-21671

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.