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TI-2024-01309 Aliases CVE-2024-1402GHSA-32h7-7j94-8fc2

Denial of service in mattermost mobile apps and server via emoji reactions

Priority LOW 21CWE-400Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · Low
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-400.

Summary

Mattermost fails to check if a custom emoji reaction exists when sending it to a post and to limit the amount of custom emojis allowed to be added in a post, allowing an attacker sending a huge amount of non-existent custom emojis in a post to crash the mobile app of a user seeing the post and to crash the server due to overloading when clients attempt to retrive the aforementioned post.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0052 44th percentileScored 2026-11-07
Fix Fixed Mattermost (Mattermost): 9.3.0, 9.2.4, 9.1.5 +1github.com/mattermost/mattermost/server/v8 (Go): 8.1.8, 9.2.4, 9.1.5

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 8.1.7; up to 9.1.4; up to 9.2.39.3.0, 9.2.4, 9.1.5, 8.1.8Patch availableCNA
—github.com/mattermost/mattermost/server/v8 (Go)before 8.1.88.1.8Patch availableGHSA-32h7-7j94-8fc2
—github.com/mattermost/mattermost/server/v8 (Go)9.2.0 to before 9.2.49.2.4Patch availableGHSA-32h7-7j94-8fc2
—github.com/mattermost/mattermost/server/v8 (Go)9.1.0 to before 9.1.59.1.5Patch availableGHSA-32h7-7j94-8fc2
  • Mattermost VendorMattermost Affected up to 8.1.7; up to 9.1.4; up to 9.2.3 Fixed in 9.3.0, 9.2.4, 9.1.5, 8.1.8 Patch available CNA
  • github.com/mattermost/mattermost/server/v8 (Go) Vendor— Affected before 8.1.8 Fixed in 8.1.8 Patch available GHSA-32h7-7j94-8fc2
  • github.com/mattermost/mattermost/server/v8 (Go) Vendor— Affected 9.2.0 to before 9.2.4 Fixed in 9.2.4 Patch available GHSA-32h7-7j94-8fc2
  • github.com/mattermost/mattermost/server/v8 (Go) Vendor— Affected 9.1.0 to before 9.1.5 Fixed in 9.1.5 Patch available GHSA-32h7-7j94-8fc2

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*up to 8.1.7; 9.0.0 – 9.1.4; 9.2.0 – 9.2.3VulnerableMattermost
  • cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:* Versions up to 8.1.7; 9.0.0 – 9.1.4; 9.2.0 – 9.2.3 Vulnerable ·Mattermost

Remediation

  • Fix · CNA Mattermost (Mattermost) Fixed in 9.3.0, 9.2.4, 9.1.5, 8.1.8
  • Fix · GHSA-32h7-7j94-8fc2 github.com/mattermost/mattermost/server/v8 (Go) Fixed in 8.1.8 Advisory →
  • Fix · GHSA-32h7-7j94-8fc2 github.com/mattermost/mattermost/server/v8 (Go) Fixed in 9.2.4 Advisory →
  • Fix · GHSA-32h7-7j94-8fc2 github.com/mattermost/mattermost/server/v8 (Go) Fixed in 9.1.5 Advisory →

Timeline

  1. 2026-10-02 Threatist record created from CVE-2024-1402
  2. 2026-10-03 Alias added: GHSA-32h7-7j94-8fc2

References

Advisory 2

Other 4

  • TI-2025-18933 Arbitrary file read in Mattermost Boards via import & export board archive CVSS 3.1CRITICAL 9.9
  • TI-2025-04465 Path Traversal Leading to RCE by Any Authenticated Mattermost User CVSS 3.1CRITICAL 9.9
  • TI-2017-14068 An issue was discovered in Mattermost Server before 3.6.2. CVSS 3.1CRITICAL 9.8
  • TI-2017-14060 An issue was discovered in Mattermost Server before 3.8.2, 3.7.5, and 3.6.7. CVSS 3.1CRITICAL 9.8
  • TI-2017-14048 An issue was discovered in Mattermost Server before 4.1.0, 4.0.4, and 3.10.3. CVSS 3.1CRITICAL 9.8
  • TI-2025-14360 Arbitrary file read via block duplication in Mattermost Boards CVSS 3.1CRITICAL 9.9
See all 505 →

Sources

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