Medium severity · published Apr 28, 2026
CVE-2026-42420
OpenClaw < 2026.4.8 - Improper Base64 Decoding Size Validation
6.5
CVSS
0.3%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 23% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
OpenClaw · OpenClaw
before 2026.4.8 · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-42420
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-42420
Patch
https://github.com/openclaw/openclaw/commit/d7c3210cd6f5fdfdc1beff4c9541673e814354d5
Vendor Advisory
https://github.com/openclaw/openclaw/security/advisories/GHSA-ccx3-fw7q-rr2r
Third Party Advisory
https://www.vulncheck.com/advisories/openclaw-improper-base64-decoding-size-validation
More from OpenClaw
9.9
CVE-2026-41329
OpenClaw < 2026.3.31 - Sandbox Bypass via Heartbeat Context Inheritance and senderIsOwner Escalation
9.9
CVE-2026-33579
OpenClaw < 2026.3.28 - Privilege Escalation via Missing Caller Scope Validation in Device Pair Approval
9.9
CVE-2026-32922
OpenClaw < 2026.3.11 - Privilege Escalation via Unvalidated Scope in device.token.rotate
9.9
CVE-2026-32048
OpenClaw < 2026.3.1 - Sandbox Escape via Cross-Agent sessions_spawn
9.9
CVE-2026-22172
OpenClaw < 2026.3.12 - Scope Elevation in WebSocket Shared-Auth Connections