CVE-2021-29504: WP-CLI is the command-line interface for WordPress

This month

CRITICAL 9.1REMOTEUPGRADE

CVE-2021-29504 is a critical-severity flaw (CVSS 9.1) affecting wp-cli. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

WP-CLI is the command-line interface for WordPress. An improper error handling in HTTPS requests management in WP-CLI version 0.12.0 and later allows remote attackers able to intercept the communication to remotely disable the certificate verification on WP-CLI side, gaining full control over the communication content, including the ability to impersonate update servers and push malicious updates towards WordPress instances controlled by the vuln

Why this priority

Critical severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	9.1 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.3% (top 29%)
CISA exploited list	No
Weakness	CWE-295
Published	2021-06-07
Last modified	2026-06-17

Publisher (CNA): GitHub, Inc. · Vendor: wp-cli

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

Am I affected?

Timeline

2021-06-07 21:15 UTCPublished CVE record published
2026-06-17 03:47 UTCUpdated Record last modified

wp-cli wp-cli UPGRADE

Affected: >= 0.12.0 and < 2.5.0

Fixed in: 2.5.0

Safe to downgrade to: a release before 0.12.0

1. Check installed version

apt-cache policy wp-cli || rpm -q wp-cli || wp-cli --version

2. UPGRADE to 2.5.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade wp-cli

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade wp-cli

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 0.12.0 (Debian / Ubuntu)

apt-cache madison wp-cli sudo apt install wp-cli=<VERSION_BEFORE_0.12.0> sudo apt-mark hold wp-cli

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

dnf --showduplicates list wp-cli sudo dnf downgrade wp-cli-<VERSION_BEFORE_0.12.0> sudo dnf versionlock add wp-cli

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-2021-29504?

wp-cli: upgrade to 2.5.0. Exact commands for each OS are on this page.

Is CVE-2021-29504 being exploited?

CVE-2021-29504 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-2021-29504 affect?

CVE-2021-29504 affects wp-cli. Severity is critical (CVSS 9.1). WP-CLI is the command-line interface for WordPress. An improper error handling in HTTPS requests management in WP-CLI version 0.12.0 and later allows remote attackers able to intercept the communication to remotely disable the certificate v

How urgent is CVE-2021-29504?

Priority 55/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

WordPress vulnerabilities

References

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