CVE-2021-3839: A flaw was found in the vhost library in DPDK

This month

HIGH 7.5REMOTEWATCHLISTUPGRADEMITIGATEMITIGATE

CVE-2021-3839 is a high-severity flaw (CVSS 7.5) affecting data plane development kit, fedora, enterprise linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A flaw was found in the vhost library in DPDK. Function vhost_user_set_inflight_fd() does not validate `msg->payload.inflight.num_queues`, possibly causing out-of-bounds memory read/write. Any software using DPDK vhost library may crash as a result of this vulnerability.

Why this priority

High severity
Remotely exploitable, no login, no user action
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 23%)
CISA exploited list	No
Weakness	CWE-125, CWE-787
Published	2022-08-23
Last modified	2026-06-17

Publisher (CNA): Red Hat, Inc. · Vendor: dpdk · fedoraproject · redhat

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

Am I affected?

Timeline

2022-08-23 16:15 UTCPublished CVE record published
2026-06-17 04:05 UTCUpdated Record last modified

dpdk data plane development kit UPGRADE

Affected: < 22.03 · 22.03 rc1 · 22.03 rc2 · 22.03 rc3

Fixed in: 22.03

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy data-plane-development-kit || rpm -q data-plane-development-kit || data-plane-development-kit --version

2. UPGRADE to 22.03 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade data-plane-development-kit

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade data-plane-development-kit

Note

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

fedoraproject fedora MITIGATE

Affected: 35

Fixed in: no fixed release known

Safe to downgrade to: a release before 35

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux MITIGATE

Affected: 7.0 · 8.0 · 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

redhat enterprise linux fast datapath DOWNGRADE

Affected: 7.0 · 8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 7.0

1. Check installed version

apt-cache policy enterprise-linux-fast-datapath || rpm -q enterprise-linux-fast-datapath || enterprise-linux-fast-datapath --version

2. No fixed release: DOWNGRADE to a release before 7.0 (Debian / Ubuntu)

apt-cache madison enterprise-linux-fast-datapath sudo apt install enterprise-linux-fast-datapath=<VERSION_BEFORE_7.0> sudo apt-mark hold enterprise-linux-fast-datapath

2. No fixed release: DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list enterprise-linux-fast-datapath sudo dnf downgrade enterprise-linux-fast-datapath-<VERSION_BEFORE_7.0> sudo dnf versionlock add enterprise-linux-fast-datapath

Downgrade risk

Downgrading can break dependent software and may reopen older bugs. Read the distro advisory first and test on a non-production host.

After downgrade

Restart the service, and keep the package held until a fixed release ships.

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-2021-3839?

data plane development kit: upgrade to 22.03; fedora: mitigate or apply the listed mitigation; enterprise linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-3839 being exploited?

CVE-2021-3839 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-2021-3839 affect?

CVE-2021-3839 affects data plane development kit, fedora, enterprise linux. Severity is high (CVSS 7.5). A flaw was found in the vhost library in DPDK. Function vhost_user_set_inflight_fd() does not validate `msg->payload.inflight.num_queues`, possibly causing out-of-bounds memory read/write. Any software using DPDK vhost library may crash as

How urgent is CVE-2021-3839?

Priority 56/100. High severity; Remotely exploitable, no login, no user action; On your watchlist

Related CVEs

CVE-2022-2132 HIGH 8.6 UPGRADE MITIGATE A permissive list of allowed inputs flaw was found in DPDK
CVE-2022-28199 MEDIUM 6.5 UPGRADE NVIDIA’s distribution of the Data Plane Development Kit (MLNX_DPDK) contains a vulnerability in the network st
CVE-2022-0669 MEDIUM 6.5 UPGRADE DOWNGRADE A flaw was found in dpdk

References

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