CVE-2026-53823: OpenClaw < 2026.5.3 - Privilege Escalation via Mutable Slack Display Names in allowFrom

Synopsis

This is an authentication bypass leading to privilege escalation in OpenClaw, a product that uses Slack display names to gate access via its allowFrom feature. The vulnerability is reachable over the network and requires a low-privilege account (any Slack account with the ability to change display names). A successful attacker can impersonate another identity by renaming their Slack display name to match an allowFrom policy entry, gaining unauthorized agent access that was intended for a different user or role. A patched-image rebuild at version 2026.5.3 is available on HarborGuard for affected environments.

HarborGuard Coverage

Exploit Conditions

• Network reachabilityRequired

  The attacker must reach the OpenClaw service over the network to leverage the renamed Slack display name against the allowFrom policy check.

• AuthenticationRequired

  The attacker needs a low-privilege Slack account with permission to change display name metadata; no admin access is required.

• Victim interactionNot required

  No victim action is needed; the attacker autonomously changes their own display name to trigger the policy match.

• Attack complexityDetail

  The exploit is reliable and condition-free; no race conditions or special environmental factors are required to rename a Slack display name and satisfy the allowFrom check.

Blast Radius

• Reads data and resources accessible to the impersonated agent identity, which may include sensitive pipeline outputs, credentials, or internal service responses (VC:H).
• Modifies data or triggers actions within the scope of the impersonated agent, such as altering workflow configurations or issuing commands on behalf of another user (VI:H).
• Service availability is not directly affected by this exploit (VA:N).
• Impact is contained to the vulnerable OpenClaw instance; no lateral scope expansion to external systems is indicated by the CVSS vector (SC:N, SI:N, SA:N).