Paper/Archive/CVE-2026-89035

CVE-2026-89035

MikroTik RouterOS — MikroTik RouterOS 7.24.5 WebFig Session Token Replay Authentication Bypass

Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
RouterOS≤ 7.23.6–CNA
RouterOS7.24.0 – 7.24.5–CNA

Scores by source

VulnCheck (CNA)9.1CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
VulnCheck (CNA)7.4CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total

References

writeupvulncheck.com/advisories/mikrotik-routeros-webfig-session-token-replay-authentication-bypass