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OpenAdvisories
High · 7.5 CVE-2026-25791 EUVD-2026-6853GHSA-wxrw-gvg8-fqjpGO-2026-4466

Sliver has a DNS C2 OTP Bypass Allows Unauthenticated Session Flooding and Denial of Service

Published Feb 9, 2026 · Updated Feb 10, 2026 · Assigned by GitHub_M

Description

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.

Affected products

VendorProductAffectedFixed
BishopFox sliver < 1.7.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
openSUSE Leap 16.0 govulncheck-vulndb 0.0.20260723T184607-160000.1.1 openSUSE-SU-2026:21483-1
openSUSE Leap 15.6 govulncheck-vulndb 0.0.20260226T182644-150000.1.149.1 SUSE-SU-2026:0757-1

Affected packages

EcosystemPackageAffectedFixedRecord
Go github.com/bishopfox/sliver < 1.6.12 1.6.12 GHSA-wxrw-gvg8-fqjp
Go github.com/bishopfox/sliver all versions — GO-2026-4466

Advisories 2

References