What’s Vulnerable › Vulnerabilities

CVE-2026-41351: OpenClaw < 2026.3.31 - Webhook Replay Detection Bypass via Base64 Signature Re-encoding

• Severity: medium (CVSS 5.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-23 · updated 2026-06-17
• Weakness: CWE-294

Description

OpenClaw before 2026.3.31 contains a replay detection bypass vulnerability in webhook signature handling that treats Base64 and Base64URL encoded signatures as distinct requests. Attackers can re-encode Telnyx webhook signatures to bypass replay detection while maintaining valid signature verification.

Affected products

• OpenClaw: before 2026.3.31 — fixed in 2026.3.31

How to fix

Upgrade to a fixed version: OpenClaw 2026.3.31. Check the vendor advisory for mitigations.

References

• https://github.com/openclaw/openclaw/commit/ad77666054651c1fd77b1dc60fd6a8db6600a29a
• https://github.com/openclaw/openclaw/security/advisories/GHSA-37v6-fxx8-xjmx
• https://www.vulncheck.com/advisories/openclaw-webhook-replay-detection-bypass-via-base64-signature-re-encoding

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