CVE-2021-31922: An HTTP Request Smuggling vulnerability in Pulse Secure Virtual Traffic Manager before 21.1 could allow an att

This week

HIGH 7.5REMOTEUPGRADE

CVE-2021-31922 is a high-severity flaw (CVSS 7.5) affecting virtual traffic manager. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An HTTP Request Smuggling vulnerability in Pulse Secure Virtual Traffic Manager before 21.1 could allow an attacker to smuggle an HTTP request through an HTTP/2 Header. This vulnerability is resolved in 21.1, 20.3R1, 20.2R1, 20.1R2, 19.2R4, and 18.2R3.

Why this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

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	1.0% (top 38%)
CISA exploited list	No
Weakness	CWE-444
Published	2021-05-14
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: pulsesecure

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

Am I affected?

Timeline

2021-05-14 01:15 UTCPublished CVE record published
2026-06-17 03:52 UTCUpdated Record last modified

pulsesecure virtual traffic manager UPGRADE

Affected: <= 18.1 · >= 18.3 and <= 19.1 · 18.2 · 18.2 r1 · 19.2 · 19.2 r1 · 19.2 r2 · 19.3

Fixed in: newer than 19.1

Safe to downgrade to: a release before 18.2

1. Check installed version

apt-cache policy virtual-traffic-manager || rpm -q virtual-traffic-manager || virtual-traffic-manager --version

2. UPGRADE to newer than 19.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade virtual-traffic-manager

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade virtual-traffic-manager

Note

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

3. If no update is available yet, DOWNGRADE to a release before 18.2 (Debian / Ubuntu)

apt-cache madison virtual-traffic-manager sudo apt install virtual-traffic-manager=<VERSION_BEFORE_18.2> sudo apt-mark hold virtual-traffic-manager

3. If no update is available yet, DOWNGRADE (RHEL / Amazon Linux / Fedora)

dnf --showduplicates list virtual-traffic-manager sudo dnf downgrade virtual-traffic-manager-<VERSION_BEFORE_18.2> sudo dnf versionlock add virtual-traffic-manager

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-2021-31922?

virtual traffic manager: upgrade to newer than 19.1. Exact commands for each OS are on this page.

Is CVE-2021-31922 being exploited?

CVE-2021-31922 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-2021-31922 affect?

CVE-2021-31922 affects virtual traffic manager. Severity is high (CVSS 7.5). An HTTP Request Smuggling vulnerability in Pulse Secure Virtual Traffic Manager before 21.1 could allow an attacker to smuggle an HTTP request through an HTTP/2 Header. This vulnerability is resolved in 21.1, 20.3R1, 20.2R1, 20.1R2, 19.2R4,

How urgent is CVE-2021-31922?

Priority 52/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2026-8051 HIGH 7.2 UPGRADE OS command injection in Ivanti Virtual Traffic Manager before version 22.9r4 allows a remote authenticated att
CVE-2024-7593 CRITICAL 9.8 EXPLOITED DOWNGRADE Ivanti Virtual Traffic Manager Authentication Bypass Vulnerability

References

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