CVE-2026-67277
Kernel memory disclosure and denial of service in MikroTik RouterOS btest service
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
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)
Official description from the CVE record, published by CERT-PL. Copyright © 1999-2026 The MITRE Corporation. See /security/cve/legal for the CVE license. View the record on cve.org
Key data
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
Attack vector: Network
The vulnerable component can be reached over a network, possibly from the Internet.
Attack complexity: Low
No measurable action is needed to get around the system's built-in security controls. The attack is repeatable.
Attack requirements: None
The attack works without any special deployment or execution conditions.
Privileges required: None
No account or privileges are needed.
User interaction: None
No action from any user is needed.
Vulnerable system: confidentiality: Low
Limited effect on the secrecy of data.
Vulnerable system: integrity: None
No effect on the trustworthiness of data.
Vulnerable system: availability: High
Serious or total effect on availability.
Subsequent systems: confidentiality: None
No effect on other systems' data secrecy.
Subsequent systems: integrity: None
No effect on other systems' data trustworthiness.
Subsequent systems: availability: None
No effect on other systems' availability.
| Metric | Value | What it means |
|---|---|---|
| Attack vector | Network | The vulnerable component can be reached over a network, possibly from the Internet. |
| Attack complexity | Low | No measurable action is needed to get around the system's built-in security controls. The attack is repeatable. |
| Attack requirements | None | The attack works without any special deployment or execution conditions. |
| Privileges required | None | No account or privileges are needed. |
| User interaction | None | No action from any user is needed. |
| Vulnerable system: confidentiality | Low | Limited effect on the secrecy of data. |
| Vulnerable system: integrity | None | No effect on the trustworthiness of data. |
| Vulnerable system: availability | High | Serious or total effect on availability. |
| Subsequent systems: confidentiality | None | No effect on other systems' data secrecy. |
| Subsequent systems: integrity | None | No effect on other systems' data trustworthiness. |
| Subsequent systems: availability | None | No effect on other systems' availability. |
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- Score
- 0.01560 (1.6% probability)
- Percentile
- 75.4%
- Scores of
- Nov 10, 2026
- Model
- v2026.06.15
- Name in the catalog
- MikroTik RouterOS Missing Authentication for Critical Function Vulnerability
- Added to the catalog
- Sep 10, 2026
- Federal due date
- Sep 13, 2026
- Exploitation
- Recorded by CISA as active
- Automatable
- yes
- Technical impact
- partial
- CWE-306Missing Authentication for Critical Functionality
Mikrotik RouterOS
- affected: 7.24 up to before 7.24.2
- affected: 7.0.0 up to before 7.23.4
- affected: 6.0.0 up to before 6.49.21
- cert.plthird-party-advisory
- cert.pltechnical-description
- npratley.netexploit
- mikrotik.comvendor-advisory
- forum.mikrotik.comrelease-notes
- forum.mikrotik.comrelease-notes
- forum.mikrotik.comrelease-notes
- ID reserved
- Record published
- Added to CISA KEV
- Record last updated
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Data from the CVE Program (MITRE), CISA KEV and FIRST EPSS. CVSS is owned by FIRST and used by permission. Not affiliated with or endorsed by MITRE, CISA or FIRST. Data as of Nov 10, 2026, 19:06 UTC. Sources and licenses