Auth bypass in Openclaw
CVE-2026-100538
OpenClaw (npm package 'openclaw') before 2026.8.1 does not apply the originating sender's global or per-agent toolsBySender policy when handling outbound attachments. A sender that has been explicitly denied filesystem read tools can still cause a known local file to be read and returned via a final-response media directive or a message attachment, disclosing local file contents to an admitted requester whose agent turn did not include the read tool. Exploitation requires knowledge or derivation of a useful host path and a delivery flow that accepts local attachments. The issue is fixed in version 2026.8.1.
Vulnerability class: Broken Access Control
Published · last modified .
CVSS v3 metric
CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (17.5th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 18th percentile — 17.5% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- GitHub Security Advisory (GHSA-w5x7-c87m-3jpc) (vendor-advisory)
- VulnCheck Advisory: OpenClaw before 2026.8.1 Local File Read via Outbound Attachments (third-party-advisory)
Frequently asked questions
- What is CVE-2026-100538?
- CVE-2026-100538 is a medium-severity vulnerability in Openclaw, classified under Incorrect Authorization. CVSS score: 6.5/10. Published 2026-09-26.
- How severe is CVE-2026-100538?
- Medium severity. CVSS v3 base score is 6.5 out of 10.