CVE-2021-34421: The Keybase Client for Android before version 5.8.0 and the Keybase Client for iOS before version 5.8.0 fails

Routine

LOW 3.7REMOTEDOWNGRADEDOWNGRADE

CVE-2021-34421 is a low-severity flaw (CVSS 3.7) affecting keybase, keybase. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

The Keybase Client for Android before version 5.8.0 and the Keybase Client for iOS before version 5.8.0 fails to properly remove exploded messages initiated by a user if the receiving user places the chat session in the background while the sending user explodes the messages. This could lead to disclosure of sensitive information which was meant to be deleted from the customer's device.

Why this priority

Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	3.7 (Low)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	0.7% (top 46%)
CISA exploited list	No
Weakness	CWE-459
Published	2021-11-11
Last modified	2026-06-17

Publisher (CNA): Zoom Video Communications, Inc. · Vendor: keybase

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

Am I affected?

Timeline

2021-11-11 23:15 UTCPublished CVE record published
2026-06-17 03:55 UTCUpdated Record last modified

keybase keybase DOWNGRADE

Affected: 5.8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.8.0

1. Check installed version

apt-cache policy keybase || rpm -q keybase || keybase --version

2. No fixed release: DOWNGRADE to a release before 5.8.0 (Debian / Ubuntu)

apt-cache madison keybase sudo apt install keybase=<VERSION_BEFORE_5.8.0> sudo apt-mark hold keybase

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

dnf --showduplicates list keybase sudo dnf downgrade keybase-<VERSION_BEFORE_5.8.0> sudo dnf versionlock add keybase

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.

keybase keybase DOWNGRADE

Affected: 5.8.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 5.8.0

1. Check installed version

apt-cache policy keybase || rpm -q keybase || keybase --version

2. No fixed release: DOWNGRADE to a release before 5.8.0 (Debian / Ubuntu)

apt-cache madison keybase sudo apt install keybase=<VERSION_BEFORE_5.8.0> sudo apt-mark hold keybase

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

dnf --showduplicates list keybase sudo dnf downgrade keybase-<VERSION_BEFORE_5.8.0> sudo dnf versionlock add keybase

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-2021-34421?

keybase: downgrade or apply the listed mitigation; keybase: downgrade or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-34421 being exploited?

CVE-2021-34421 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-2021-34421 affect?

CVE-2021-34421 affects keybase, keybase. Severity is low (CVSS 3.7). The Keybase Client for Android before version 5.8.0 and the Keybase Client for iOS before version 5.8.0 fails to properly remove exploded messages initiated by a user if the receiving user places the chat session in the background while the

How urgent is CVE-2021-34421?

Priority 31/100. Remotely exploitable, no login, no user action

Software pages

Android vulnerabilities · iOS vulnerabilities

Related CVEs

CVE-2022-22779 LOW 3.7 UPGRADE The Keybase Clients for macOS and Windows before version 5.9.0 fails to properly remove exploded messages init
CVE-2021-34426 MEDIUM 5.3 UPGRADE A vulnerability was discovered in the Keybase Client for Windows before version 5.6.0 when a user executed the
CVE-2021-34422 HIGH 7.2 UPGRADE The Keybase Client for Windows before version 5.7.0 contains a path traversal vulnerability when checking the
CVE-2021-23827 MEDIUM 5.5 UPGRADE UPGRADE Keybase Desktop Client before 5.6.0 on Windows and macOS, and before 5.6.1 on Linux, allows an attacker to obt

References

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