CVE-2026-53837 PUBLISHED

OpenClaw < 2026.5.6 - Missing Channel Type Validation in Mattermost Event Handlers

Assigner: VulnCheck
Reserved: 10.06.2026 Published: 12.06.2026 Updated: 12.06.2026

OpenClaw before 2026.5.6 contains an improper access control vulnerability in Mattermost event handlers that fails to validate channel type metadata. Attackers can bypass intended DM policy decisions by sending crafted Mattermost events missing channel type information to process restricted content.

CVSS Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
CVSS Score: 6.3

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Network	Confidentiality	None	Confidentiality	None
Attack Complexity	High	Integrity	Low	Integrity	None
Attack Requirements	Present	Availability	None	Availability	None
Privileges Required	None
User Interaction	None

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N
CVSS Score: 3.7

Attack Vector	Network	Scope	Unchanged
Attack Complexity	High	Confidentiality Impact	None
Privileges Required	None	Integrity Impact	Low
User Interaction	None	Availability Impact	None

CVSS 3.1

Product Status

Vendor	OpenClaw
Product	OpenClaw
Versions	Default: unaffected affected from 0 to 2026.5.6 (excl.) Version 2026.5.6 is unaffected

CVE-2026-53837 PUBLISHED

OpenClaw < 2026.5.6 - Missing Channel Type Validation in Mattermost Event Handlers

Metrics

Product Status

Credits

References

Problem Types