CVE-2021-36383: Xen Orchestra (with xo-web through 5.80.0 and xo-server through 5.84.0) mishandles authorization, as demonstra

Q: How do I fix CVE-2021-36383?

xo-server: upgrade to newer than 5.84.0; xo-web: upgrade to newer than 5.80.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-36383 being exploited?

CVE-2021-36383 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-36383 affect?

CVE-2021-36383 affects xo-server, xo-web. Severity is medium (CVSS 4.3). Xen Orchestra (with xo-web through 5.80.0 and xo-server through 5.84.0) mishandles authorization, as demonstrated by modified WebSocket resourceSet.getAll data is which the attacker changes the permission field from none to admin. The attac

Q: How urgent is CVE-2021-36383?

Priority 33/100. Public exploit reference

Routine

MEDIUM 4.3UPGRADEUPGRADE

CVE-2021-36383 is a medium-severity flaw (CVSS 4.3) affecting xo-server, xo-web. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Xen Orchestra (with xo-web through 5.80.0 and xo-server through 5.84.0) mishandles authorization, as demonstrated by modified WebSocket resourceSet.getAll data is which the attacker changes the permission field from none to admin. The attacker gains access to data sets such as VMs, Backups, Audit, Users, and Groups.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	4.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.7% (top 46%)
CISA exploited list	No
Published	2021-07-12
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: xen-orchestra

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-07-12 14:15 UTCPublished CVE record published
2026-06-17 03:58 UTCUpdated Record last modified

xen-orchestra xo-server UPGRADE

Affected: <= 5.84.0

Fixed in: newer than 5.84.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy xo-server || rpm -q xo-server || xo-server --version

2. UPGRADE to newer than 5.84.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade xo-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade xo-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

xen-orchestra xo-web UPGRADE

Affected: <= 5.80.0

Fixed in: newer than 5.80.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy xo-web || rpm -q xo-web || xo-web --version

2. UPGRADE to newer than 5.80.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade xo-web

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade xo-web

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2021-36383?

xo-server: upgrade to newer than 5.84.0; xo-web: upgrade to newer than 5.80.0. Exact commands for each OS are on this page.

Is CVE-2021-36383 being exploited?

CVE-2021-36383 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2021-36383 affect?

CVE-2021-36383 affects xo-server, xo-web. Severity is medium (CVSS 4.3). Xen Orchestra (with xo-web through 5.80.0 and xo-server through 5.84.0) mishandles authorization, as demonstrated by modified WebSocket resourceSet.getAll data is which the attacker changes the permission field from none to admin. The attac

How urgent is CVE-2021-36383?

Priority 33/100. Public exploit reference

Software pages

Xen vulnerabilities

References

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