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TI-2026-18371 Aliases CVE-2026-22880GHSA-j628-rc2h-qj7g

Mobile SSO authentication flow allows credential theft via malicious server

Priority LOW 26CWE-352Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
Required
Attack complexity
High
Impact type
Tampering
Confidentiality · integrity · availability
High · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-352.

Summary

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 it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00117 1st percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 2.38.0, 11.5.0, 2.37.1.0 +4

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
MattermostMattermostup to 2.0.37; up to 11.0.4; up to 11.1.3; up to 11.3.2; up to 10.11.112.38.0, 11.5.0, 2.37.1.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12Patch availableCNA
  • Mattermost VendorMattermost Affected up to 2.0.37; up to 11.0.4; up to 11.1.3; up to 11.3.2; up to 10.11.11 Fixed in 2.38.0, 11.5.0, 2.37.1.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mattermost:mattermost_mobile:*:*:*:*:*:*:*:*before 2.37.1VulnerableMattermost
  • cpe:2.3:a:mattermost:mattermost_mobile:*:*:*:*:*:*:*:* Versions before 2.37.1 Vulnerable ·Mattermost

Remediation

  • Fix · CNA Mattermost (Mattermost) Fixed in 2.38.0, 11.5.0, 2.37.1.0, 11.4.1, 11.3.2, 11.2.4, 10.11.12

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-22880
  2. 2026-10-03 Alias added: GHSA-j628-rc2h-qj7g

References

Advisory 1

  • TI-2020-11312 An issue was discovered in Mattermost Mobile Apps before 1.29.0. CVSS 3.1HIGH 7.5
  • TI-2020-11310 An issue was discovered in Mattermost Mobile Apps before 1.30.0. CVSS 3.1HIGH 7.5
  • TI-2019-15070 An issue was discovered in Mattermost Mobile Apps before 1.26.0. CVSS 3.1HIGH 7.5
  • TI-2019-15066 An issue was discovered in Mattermost Mobile Apps before 1.26.0. CVSS 3.1HIGH 7.5
  • TI-2025-14702 Mobile crash via object that can't be cast to String in Attachment Field CVSS 3.1HIGH 7.5
  • TI-2025-14379 Mobile crash via improper validation of proto style in attachments CVSS 3.1HIGH 7.5
See all 20 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences