CVE-2021-27229: Mumble before 1.3.4 allows remote code execution if a victim navigates to a crafted URL on a server list and c

Q: How do I fix CVE-2021-27229?

mumble: upgrade to 1.3.4; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Q: Is CVE-2021-27229 being exploited?

CVE-2021-27229 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-2021-27229 affect?

CVE-2021-27229 affects mumble, debian linux. Severity is high (CVSS 8.8). Mumble before 1.3.4 allows remote code execution if a victim navigates to a crafted URL on a server list and clicks on the Open Webpage text.

Q: How urgent is CVE-2021-27229?

Priority 58/100. High severity; On your watchlist

This month

HIGH 8.8WATCHLISTUPGRADEMITIGATE

CVE-2021-27229 is a high-severity flaw (CVSS 8.8) affecting mumble, debian linux. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Mumble before 1.3.4 allows remote code execution if a victim navigates to a crafted URL on a server list and clicks on the Open Webpage text.

Why this priority

High severity
On your watchlist

A fixed release or distro patch exists.

Risk facts

CVSS score	8.8 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	3.2% (top 12%)
CISA exploited list	No
Weakness	CWE-59
Published	2021-02-16
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: debian · mumble

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

Am I affected?

Timeline

2021-02-16 04:15 UTCPublished CVE record published
2026-06-17 03:44 UTCUpdated Record last modified

mumble mumble UPGRADE

Affected: < 1.3.4

Fixed in: 1.3.4

Safe to downgrade to: no unaffected older release

1. Check installed version

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

2. UPGRADE to 1.3.4 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mumble

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mumble

Note

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

debian debian linux MITIGATE

Affected: 9.0

Fixed in: no fixed release known

Safe to downgrade to: a release before 9.0

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.

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-2021-27229?

mumble: upgrade to 1.3.4; debian linux: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2021-27229 being exploited?

CVE-2021-27229 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-2021-27229 affect?

CVE-2021-27229 affects mumble, debian linux. Severity is high (CVSS 8.8). Mumble before 1.3.4 allows remote code execution if a victim navigates to a crafted URL on a server list and clicks on the Open Webpage text.

How urgent is CVE-2021-27229?

Priority 58/100. High severity; On your watchlist

Software pages

Debian vulnerabilities

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References

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