CVE-2026-2456

Summary

Mattermost versions 11.3.x <= 11.3.0, 11.2.x <= 11.2.2, 10.11.x <= 10.11.10 Mattermost fails to limit the size of responses from integration action endpoints, which allows an authenticated attacker to cause server memory exhaustion and denial of service via a malicious integration server that returns an arbitrarily large response when a user clicks an interactive message button.. Mattermost Advisory ID: MMSA-2026-00571

Affected Software

VendorProductVersion RangeStatus
MattermostMattermost11.3.0 <= 11.3.0affected
MattermostMattermost11.2.0 <= 11.2.2affected
MattermostMattermost10.11.0 <= 10.11.10affected
MattermostMattermost11.4.0unaffected
MattermostMattermost11.3.1unaffected
MattermostMattermost11.2.3unaffected
MattermostMattermost10.11.11unaffected

Weaknesses

  • CWE-789: CWE-789: Memory Allocation with Excessive Size Value

ADP Enrichment

CISA ADP Vulnrichment

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

References