Openclaw EUVD-2026-21486

The CVSS score of 5.9 (Medium) reflects a credible but constrained threat. The attack vector is network-based (AV:N) with high complexity (AC:H), requiring authentication (PR:L), and resulting in high confidentiality impact (C:H) and low integrity impact (I:L). The AC:H modifier significantly lowers urgency-successful exploitation requires the attacker to manipulate username resolution timing and conditions, suggesting environmental preconditions or race conditions may be necessary. EPSS data is not provided, but the requirement for prior authentication (PR:L) and the complexity of username rebinding coordination substantially reduce the likelihood of opportunistic exploitation compared to unauthenticated remote code execution vulnerabilities. Patch availability from the vendor further de-risks this issue for organizations that can apply updates. The lack of known public exploit code or CISA KEV confirmation indicates this is not an imminent mass-exploitation threat, though the technical impact (redirecting sensitive communication) makes timely patching important for organizations using OpenClaw webhooks. This is a genuine but lower-urgency priority compared to high-impact, low-complexity vulnerabilities.

An authenticated attacker with access to OpenClaw monitors a webhook integration (e.g., a support ticketing system sending replies into OpenClaw chat). When a webhook event arrives containing a username-based recipient binding for user alice, the attacker changes their own username to alice or exploits a username collision/race condition at the moment the webhook is processed. The webhook reply-which may contain sensitive information like password reset links or private support information-is delivered to the attacker instead of alice. AC:H suggests this timing must align with specific conditions, but in organizations with frequent webhook traffic or predictable timing, successful exploitation is feasible.