Resource exhaustion in Openclaw
CVE-2026-42420
OpenClaw before 2026.4.8 contains improper input validation in base64 decode paths that allocate memory before enforcing decoded-size limits. Attackers can exploit multiple code paths to cause memory exhaustion or denial of service through crafted base64-encoded input.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L.
EPSS exploit prediction
EPSS: 0.005 (43.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 44th percentile — 43.7% 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: 0.005 · change: +0.002
Affected products
- Openclaw — versions 0, 2026.4.8
Weakness classification (CWE)
References
- github.com/openclaw/openclaw/security/advisories/GHSA-ccx3-fw7q-rr2r (vendor-advisory, Vendor Advisory)
- github.com/openclaw/openclaw/commit/d7c3210cd6f5fdfdc1beff4c9541673e814354d5 (Patch, patch)
- www.vulncheck.com/advisories/openclaw-improper-base64-decoding-size-validation (Third Party Advisory, third-party-advisory)
Frequently asked questions
- What is CVE-2026-42420?
- CVE-2026-42420 is a medium-severity vulnerability in Openclaw, classified under Allocation of Resources Without Limits or Throttling. CVSS score: 4.3/10. Published 2026-04-28.
- How severe is CVE-2026-42420?
- Medium severity. CVSS v3 base score is 4.3 out of 10.