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.
Exploitability
AV:NAC:LAT:PPR:NUI:NVulnerable System
VC:LVI:NVA:NSubsequent System
SC:NSI:NSA:N6.3/CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:NOther