CVE-2021-21823: An information disclosure vulnerability exists in the Friend finder functionality of GmbH Komoot version 10.26

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HIGH 7.5REMOTEUPGRADE

CVE-2021-21823 is a high-severity flaw (CVSS 7.5) affecting komoot. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An information disclosure vulnerability exists in the Friend finder functionality of GmbH Komoot version 10.26.9 up to 11.1.11. A specially crafted series of network requests can lead to the disclosure of sensitive information.

Why this priority

High severity
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	0.9% (top 41%)
CISA exploited list	No
Weakness	CWE-359, CWE-200
Published	2021-08-20
Last modified	2026-06-17

Publisher (CNA): Talos · Vendor: komoot

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

Am I affected?

Timeline

2021-08-20 18:15 UTCPublished CVE record published
2026-06-17 03:36 UTCUpdated Record last modified

komoot komoot UPGRADE

Affected: >= 10.26.9 and <= 11.1.11

Fixed in: newer than 11.1.11

Safe to downgrade to: a release before 10.26.9

1. Check installed version

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

2. UPGRADE to newer than 11.1.11 (Debian / Ubuntu)

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

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade komoot

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 10.26.9 (Debian / Ubuntu)

apt-cache madison komoot sudo apt install komoot=<VERSION_BEFORE_10.26.9> sudo apt-mark hold komoot

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

dnf --showduplicates list komoot sudo dnf downgrade komoot-<VERSION_BEFORE_10.26.9> sudo dnf versionlock add komoot

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-2021-21823?

komoot: upgrade to newer than 11.1.11. Exact commands for each OS are on this page.

Is CVE-2021-21823 being exploited?

CVE-2021-21823 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-2021-21823 affect?

CVE-2021-21823 affects komoot. Severity is high (CVSS 7.5). An information disclosure vulnerability exists in the Friend finder functionality of GmbH Komoot version 10.26.9 up to 11.1.11. A specially crafted series of network requests can lead to the disclosure of sensitive information.

How urgent is CVE-2021-21823?

Priority 46/100. High severity; Remotely exploitable, no login, no user action

References

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