CVE-2026-22880: Mattermost Mobile Apps versions <=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate t

Q: How do I fix CVE-2026-22880?

mattermost mobile: upgrade to 2.37.1. Exact commands for each OS are on this page.

Q: Is CVE-2026-22880 being exploited?

CVE-2026-22880 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-2026-22880 affect?

CVE-2026-22880 affects mattermost mobile. Severity is medium (CVSS 6.1). Mattermost Mobile Apps versions <=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials

Q: How urgent is CVE-2026-22880?

Priority 22/100. No elevated risk signals yet.

Routine

MEDIUM 6.1UPGRADE

CVE-2026-22880 is a medium-severity flaw (CVSS 6.1) affecting mattermost mobile. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Mattermost Mobile Apps versions <=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials for a legitimate Mattermost server via relaying the SSO code exchange flow through the mobile application. Mattermost Advisory ID: MMSA-2025-00564

Why this priority

No elevated risk signals yet

A fixed release or distro patch exists.

Risk facts

CVSS score	6.1 (Medium)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.1% (top 98%)
CISA exploited list	No
Weakness	CWE-352
Published	2026-05-21
Last modified	2026-08-06

Publisher (CNA): Mattermost, Inc. · Vendor: mattermost

Last updated 2026-08-06 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-05-21 09:16 UTCPublished CVE record published
2026-08-06 15:42 UTCUpdated Record last modified

mattermost mattermost mobile UPGRADE

Affected: < 2.37.1

Fixed in: 2.37.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy mattermost-mobile || rpm -q mattermost-mobile || mattermost-mobile --version

2. UPGRADE to 2.37.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade mattermost-mobile

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade mattermost-mobile

Note

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

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-2026-22880?

mattermost mobile: upgrade to 2.37.1. Exact commands for each OS are on this page.

Is CVE-2026-22880 being exploited?

CVE-2026-22880 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-2026-22880 affect?

CVE-2026-22880 affects mattermost mobile. Severity is medium (CVSS 6.1). Mattermost Mobile Apps versions <=2.37 11.4 2.0.37 11.0.4 11.1.3 11.3.2 10.11.11.0 fail to properly validate the SSO authentication callback origin which allows an attacker controlling a malicious Mattermost server to steal user credentials

How urgent is CVE-2026-22880?

Priority 22/100. No elevated risk signals yet.

Software pages

Mattermost vulnerabilities

References

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