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.

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…

EPSS: 0.001 (16.1th percentile) — read the EPSS interpretation.

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.

Affected products

Openclaw — versions 0, 2026.4.8

Weakness classification (CWE)

CWE-770 — Allocation of Resources Without Limits or Throttling

References

GitHub Security Advisory (GHSA-ccx3-fw7q-rr2r) (vendor-advisory, Vendor Advisory)
Patch Commit (Patch, patch)
VulnCheck Advisory: OpenClaw < 2026.4.8 - 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.