{"id":"CVE-2026-42438","aliases":["EUVD-2026-27259","GHSA-jhpv-5j76-m56h"],"status":"published","title":"OpenClaw 2026.4.9 \u003c 2026.4.10 - Sender Policy Bypass in Host Media Attachment Reads","description":"OpenClaw versions 2026.4.9 before 2026.4.10 contain a sender policy bypass vulnerability in the outbound host-media attachment read helper that allows unauthorized local file disclosure. Attackers with denied read access via toolsBySender or group policy can trigger host-media attachment loading to bypass sender and group-scoped authorization boundaries and retrieve readable local files through the outbound media path.","severity":{"version":"4.0","score":4.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00237,"percentile":0.14807,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":true},"cwes":["CWE-863"],"published":"2026-04-17T22:17:57Z","modified":"2026-10-28T02:30:23Z","fixes":[{"ecosystem":"npm","package":"openclaw","fixed_in":["2026.4.10"],"sources":["ghsa","osv"]}],"affected":[{"source":"ghsa","ecosystem":"npm","package":"openclaw","ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2026.4.9"},{"fixed":"2026.4.10"}]}]},{"source":"osv","ecosystem":"npm","package":"openclaw","ranges":[{"type":"SEMVER","events":[{"introduced":"2026.4.9"},{"fixed":"2026.4.10"}]}]}],"products":[{"vendor":"openclaw","product":"openclaw"}],"references":[{"url":"https://github.com/openclaw/openclaw/security/advisories/GHSA-jhpv-5j76-m56h","tags":["vendor-advisory","Vendor Advisory","advisory","web"]},{"url":"https://github.com/openclaw/openclaw/commit/c949af9fabf3873b5b7c484090cb5f5ab6049a98","tags":["patch","Patch","fix","web"]},{"url":"https://www.vulncheck.com/advisories/openclaw-sender-policy-bypass-in-host-media-attachment-reads","tags":["third-party-advisory","Third Party Advisory","advisory"]},{"url":"https://github.com/openclaw/openclaw/pull/64459","tags":["web"]},{"url":"https://github.com/advisories/GHSA-jhpv-5j76-m56h"},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/42xxx/CVE-2026-42438.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-42438","tags":["advisory"]},{"url":"https://github.com/openclaw/openclaw","tags":["package"]}],"sources":{"cve":[{"id":"CVE-2026-42438","title":"OpenClaw 2026.4.9 \u003c 2026.4.10 - Sender Policy Bypass in Host Media Attachment Reads","description":"OpenClaw versions 2026.4.9 before 2026.4.10 contain a sender policy bypass vulnerability in the outbound host-media attachment read helper that allows unauthorized local file disclosure. Attackers with denied read access via toolsBySender or group policy can trigger host-media attachment loading to bypass sender and group-scoped authorization boundaries and retrieve readable local files through the outbound media path.","status":"published","published":"2026-05-05T11:24:56.718Z","modified":"2026-05-05T14:48:23.888Z","cvss":[{"version":"4.0","score":4.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N","level":"medium","assessor":"cna"},{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high","assessor":"cna"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T13:40:23.731501Z"}],"euvd":[{"id":"EUVD-2026-27259","description":"OpenClaw versions 2026.4.9 before 2026.4.10 contain a sender policy bypass vulnerability in the outbound host-media attachment read helper that allows unauthorized local file disclosure. Attackers with denied read access via toolsBySender or group policy can trigger host-media attachment loading to bypass sender and group-scoped authorization boundaries and retrieve readable local files through the outbound media path.","status":"published","published":"2026-05-05T11:24:56Z","modified":"2026-05-05T14:48:23Z","cvss":[{"version":"4.0","score":4.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N","level":"medium"}],"updated_at":"2026-11-02T19:05:17.068199Z"}],"ghsa":[{"id":"GHSA-jhpv-5j76-m56h","title":"OpenClaw: Sender policy bypass in host media attachment reads allows unauthorized local file disclosure","description":"## 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 `\u003e= 2026.4.9 \u003c 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.","status":"published","published":"2026-04-17T22:17:57Z","modified":"2026-05-05T11:49:52Z","cvss":[{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T14:40:00.970271Z"}],"nvd":[{"id":"CVE-2026-42438","description":"OpenClaw versions 2026.4.9 before 2026.4.10 contain a sender policy bypass vulnerability in the outbound host-media attachment read helper that allows unauthorized local file disclosure. Attackers with denied read access via toolsBySender or group policy can trigger host-media attachment loading to bypass sender and group-scoped authorization boundaries and retrieve readable local files through the outbound media path.","status":"published","published":"2026-05-05T12:16:18.327Z","modified":"2026-06-17T10:47:50.587Z","cvss":[{"version":"4.0","score":4.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.7,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N","level":"high","assessor":"secondary"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T14:12:17.022502Z"}],"osv":[{"id":"CVE-2026-42438","title":"OpenClaw 2026.4.9 \u003c 2026.4.10 - Sender Policy Bypass in Host Media Attachment Reads","description":"OpenClaw versions 2026.4.9 before 2026.4.10 contain a sender policy bypass vulnerability in the outbound host-media attachment read helper that allows unauthorized local file disclosure. Attackers with denied read access via toolsBySender or group policy can trigger host-media attachment loading to bypass sender and group-scoped authorization boundaries and retrieve readable local files through the outbound media path.","status":"published","published":"2026-05-05T11:24:56.718Z","modified":"2026-10-28T02:30:23.728371045Z","cvss":[{"version":"4.0","score":4.9,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:L/VI:N/VA:N/SC:H/SI:N/SA:N","level":"medium"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T15:45:04.117819Z"},{"id":"GHSA-jhpv-5j76-m56h","title":"OpenClaw: Sender policy bypass in host media attachment reads allows unauthorized local file disclosure","description":"## 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 `\u003e= 2026.4.9 \u003c 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.","status":"published","published":"2026-04-17T22:17:57Z","modified":"2026-05-05T16:11:35.126323Z","cvss":[{"version":"4.0","score":6,"vector":"CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N","level":"medium"}],"cwes":["CWE-863"],"updated_at":"2026-11-02T15:46:50.336262Z"}]}}