{"id":"CVE-2026-42438","aliases":["GHSA-jhpv-5j76-m56h"],"url":"https://o3.security/vulnerability/CVE-2026-42438","summary":"OpenClaw 2026.4.9 < 2026.4.10 - Sender Policy Bypass in Host Media Attachment Reads","details":"## Summary\n\nOpenClaw'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.\n\n## Affected Versions\n\nThis 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`.\n\n## Impact\n\nAffected 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.\n\nThe 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.\n\n## Resolution\n\nFixed 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.\n\nAdditional attachment canonicalization hardening shipped in 2026.4.14, but the authorization bypass described here was fixed in 2026.4.10.\n\n## Credit\n\nThanks to @Telecaster2147 for reporting this issue.","published":"2026-05-05T11:24:56.718Z","modified":"2026-08-12T03:51:34.267883460Z","cvss":null,"epss":{"score":0.00236,"percentile":0.14764,"asOf":"2026-08-13"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"openclaw","fixedVersion":"2026.4.10"}],"fix":{"url":"https://github.com/openclaw/openclaw/commit/c949af9fabf3873b5b7c484090cb5f5ab6049a98","label":"openclaw/openclaw@c949af9"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42438.json"},{"type":"ADVISORY","url":"https://github.com/openclaw/openclaw/security/advisories/GHSA-jhpv-5j76-m56h"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42438"},{"type":"ADVISORY","url":"https://www.vulncheck.com/advisories/openclaw-sender-policy-bypass-in-host-media-attachment-reads"},{"type":"FIX","url":"https://github.com/openclaw/openclaw/commit/c949af9fabf3873b5b7c484090cb5f5ab6049a98"},{"type":"WEB","url":"https://github.com/openclaw/openclaw/pull/64459"},{"type":"PACKAGE","url":"https://github.com/openclaw/openclaw"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:34.267883460Z"}}