Vulnerability in MikroTik RouterOS

[ Description ]Official description

MikroTik RouterOS through 7.24.5 contains a session token replay vulnerability in the WebFig interface that allows attackers to bypass authentication by replaying captured session tokens across new ECDH sessions. The makeSessionKey function in libucrypto.so generates tokens using fixed salts without incorporating channel-specific or session-specific input, and the user service validates tokens against the login store without verifying channel context, enabling stolen tokens to grant persistent administrative access until the token store is explicitly cleared. This vulnerability extends the impact of CVE-2025-61481, which identified the underlying transport-layer exposure without a corresponding fix.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ Advisories ]Government CERT advisories

• BSI CERT-Bund21 Oct 2026WID-SEC-2026-4109

  MikroTik RouterOS: Vulnerability allows bypassing security measures Translated from German

  Risk mediumCVE-2026-89035

[ References ]References

• www.vulncheck.com/advisories/mikrotik-routeros-webfig-session-token-replay-authenticati…