CVE-2026-15814

Summary

Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7, 10.11.x <= 10.11.22 fail to limit the amount of memory allocated when decoding uploaded image files which allows an authenticated user to cause excessive server memory consumption and potential denial of service via uploading a specially crafted image as a profile picture, channel file attachment, team icon, or custom brand image. Mattermost Advisory ID: MMSA-2026-00719

Affected Software

VendorProductVersion RangeStatus
MattermostMattermost11.9.0 <= 11.9.0affected
MattermostMattermost11.8.0 <= 11.8.4affected
MattermostMattermost11.7.0 <= 11.7.7affected
MattermostMattermost10.11.0 <= 10.11.22affected
MattermostMattermost11.10.0unaffected
MattermostMattermost11.9.1unaffected
MattermostMattermost11.8.5unaffected
MattermostMattermost11.7.8unaffected
MattermostMattermost10.11.23unaffected

Weaknesses

  • CWE-409: CWE-409: Improper Handling of Highly Compressed Data (Data Amplification)

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

References