CVE-2026-93345: MikroTik RouterOS < 7.25beta4 Improper Input Validation DoS via BGP Labelled-VPN NLRI
MikroTik RouterOS before 7.25beta4 contains an improper input validation vulnerability in the labelled-VPN NLRI iterators of the routing service that allows an unauthenticated on-path attacker to crash the BGP service by sending a malformed MPREACHNLRI UPDATE message with a prefix-length value below the minimum valid for a labelled-VPN NLRI, which passes validation while describing a route with a negative-length address portion. Attackers can repeatedly send a single BGP UPDATE packet carrying a VPNv4 or VPNv6 NLRI with an out-of-bounds prefix-length to indefinitely hold down the BGP plane, causing session termination without a NOTIFICATION and triggering a service malfunction on the device.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
MikroTik RouterOSto a version that resolves this vulnerability.Fixed in 7.25beta4
Event History
Frequently Asked Questions
Which RouterOS deployments are exposed?
RouterOS versions before 7.25beta4 are affected when the device processes BGP labelled-VPN NLRI, including VPNv4 or VPNv6 NLRIs.
Does an attacker need BGP credentials or administrative access?
No. Exploitation is unauthenticated, but the attacker must be on-path to send a malformed BGP UPDATE message to the targeted BGP session.
What operational signs could indicate exploitation?
The BGP service can crash and terminate sessions without sending a NOTIFICATION. Repeated malformed UPDATE packets can keep the BGP plane unavailable indefinitely.