CVE-2026-25791 — Sliver has a DNS C2 OTP Bypass Allows Unauthenticated Session Flooding and Denial of Service
Sliver is a command and control framework that uses a custom Wireguard netstack. Prior to 1.7.0, the DNS C2 listener accepts unauthenticated TOTP bootstrap messages and allocate…
Published: 2026-02-09 · CVSS: 7.5 · CVSS 3.1
Sliver is a command and control framework that uses a custom Wireguard netstack. Prior to 1.7.0, the DNS C2 listener accepts unauthenticated TOTP bootstrap messages and allocates server-side DNS sessions without validating OTP values, even when EnforceOTP is enabled. Because sessions are stored without a cleanup/expiry path in this flow, an unauthenticated remote actor can repeatedly create sessions and drive memory exhaustion. This vulnerability is fixed in 1.7.0.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7