CVE-2026-2456

Denial of Service via Unbounded Memory Allocation in Integration Actions

State: Published
Severity: 5.3 Medium
Published: Mar 16, 2026
Updated: Mar 16, 2026
Reserved: Feb 13, 2026

Description

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

Scores

CVSS	Score	Vector	Source
3.1	5.3 Medium	CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:N/A:H	Mattermost

Weaknesses

CWE-789 Memory Allocation with Excessive Size Value

Affected Products

Product	Versions
MattermostMattermost	11.3.0 through 11.3.0Affected 11.2.0 through 11.2.2Affected 10.11.0 through 10.11.10Affected 11.4.0Not affected 11.3.1Not affected 11.2.3Not affected 10.11.11Not affected

References

MMSA-2026-00571vendor-advisory

Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.