October 19, 2026

CVE Watchtower

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CVE-2026-67277NVD

Vulnerability Summary

RouterOS accepts a "related" btest connection before the corresponding primary session has completed authentication. An unauthenticated client can use this state to start an IPv4 UDP test. With "random-data=false", the sender transmits an uninitialized tail from a kernel packet buffer. A separate unchecked, inverted packet-size interval causes unsigned integer underflow, anomalously large fragmented output, and can restart the RouterOS kernel.



This issue was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)
Severity Level
UNKNOWN
Published Date
Sep 5, 2026
Last Modified
Sep 11, 2026
Exploitation Status
ACTIVE
EPSS Score (30-Day)
1.56%Probability
Root Weakness (CWE)
CWE-306: Unknown/Unlisted Weakness ↗
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.
CVSS v4.0 Base Metrics — Score 8.8 (HIGH)
Attack VectorNetwork
Attack ComplexityLow
Attack RequirementsNone
Privileges RequiredNone
User InteractionNone
Confidentiality (Vulnerable System)Low
Integrity (Vulnerable System)None
Availability (Vulnerable System)High
Confidentiality (Subsequent System)None
Integrity (Subsequent System)None
Availability (Subsequent System)None

Affected & Patched Versions

Affected Versions
  • Mikrotik RouterOS >= 7.24 and < 7.24.2
  • Mikrotik RouterOS >= 7.0.0 and < 7.23.4
  • Mikrotik RouterOS >= 6.0.0 and < 6.49.21
Patched Versions
  • Mikrotik RouterOS 7.24.2
  • Mikrotik RouterOS 7.23.4
  • Mikrotik RouterOS 6.49.21
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🎁7-Day Free Trial — Try Pro or Team, no card required.
📧Email Delivery — Threat intel straight to your inbox.
♾️Unlimited Vendors — Track your entire stack.
🚨All New CVEs — Be the first to know.
📈EPSS Spike Alerts — Catch rising risk before it peaks.
🎯Custom EPSS/CVSS — Filter noise, focus on risk.
🛡️Exploit Intel — A 2nd confirmed-exploit signal beyond KEV.
🐙GitHub Issues — Auto-tracked, no duplicates.
📬Weekly Digest — One clean summary, not inbox spam.
🏷️Watchlist Groups — Tag alerts by team (Infra/AppSec/SOC).
💬Webhooks — Slack & Teams integration.
🔀Smart Routing — Critical alerts to one channel, rest to another.
🚫Ad-Free — Uninterrupted experience.

External References