Vulnerability · Published Apr 28, 2026 · Assigned by VulnCheck
CVE-2026-42420OpenClaw < 2026.4.8 - Improper Base64 Decoding Size Validation
Medium 4.3
In plain English
A medium-severity resource allocation without limits in OpenClaw from OpenClaw. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 23% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Severity (CVSS 3.1)4.3Medium
Exploit odds (30 days)0.3%top 77.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| npm | openclaw | 2026.4.8 | GHSA-ccx3-fw7q-rr2r |
Affected products (as reported)
Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L
References
- GitHub Security Advisory (GHSA-ccx3-fw7q-rr2r) vendor-advisory
- Patch Commit patch
- VulnCheck Advisory: OpenClaw < 2026.4.8 - Improper Base64 Decoding Size Validation third-party-advisory