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.
https://github.com/openclaw/openclaw/security/advisories/GHSA-37v6-fxx8-xjmx
https://github.com/openclaw/openclaw/commit/ad77666054651c1fd77b1dc60fd6a8db6600a29a
Published: 2026-04-23
Updated: 2026-04-23
Base Score: 5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:N/A:N
Severity: Medium
Base Score: 5.3
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Severity: Medium
Base Score: 6.3
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
Severity: Medium