CVE-2026-42438

Description

## Summary OpenClaw's outbound host-media attachment read helper could enable host-local file reads based on global or agent-level read access without also honoring sender and group-scoped tool policy. In channel deployments that used `toolsBySender` or group policy to deny `read` for less-trusted senders, a denied sender could still trigger host-media attachment loading and cause readable local files to be returned through the outbound media path. ## Affected Versions This issue is known to affect OpenClaw 2026.4.9. Earlier versions were not confirmed during triage, so the advisory range is intentionally scoped to `>= 2026.4.9 < 2026.4.10`. ## Impact Affected deployments are those that both allow host read or filesystem root expansion at the global/agent level and rely on sender or group-scoped policy to deny `read` for some channel participants. In that configuration, the intended sender/group authorization boundary could be bypassed for outbound media reads, potentially disclosing host-local files readable by the OpenClaw process. The issue does not require treating the model prompt as the security boundary. The vulnerable behavior was a concrete policy enforcement mismatch: sender/group policy denied `read`, while the host-media read helper could still be installed without that sender context. ## Resolution Fixed in OpenClaw 2026.4.10 by PR #64459, commit `c949af9fabf3873b5b7c484090cb5f5ab6049a98`. The fix threads sender, session, channel, and account context into outbound media access resolution and intersects host-media read capability creation with the existing group tool policy for `read`. When a concrete sender/group override denies `read`, OpenClaw no longer creates the host `readFile` media capability. Additional attachment canonicalization hardening shipped in 2026.4.14, but the authorization bypass described here was fixed in 2026.4.10. ## Credit Thanks to @Telecaster2147 for reporting this issue.

How to fix CVE-2026-42438

To remediate CVE-2026-42438, upgrade the affected package to a fixed version below.

• —upgrade to 2026.4.10 or later

Is CVE-2026-42438 being exploited?

Low — EPSS is 0.0%, meaning exploitation activity has not been observed at scale.