CVE Details

CVE-2026-67277 MikroTik RouterOS Missing Authentication for Critical Function Vulnerability
Published: 2026-09-10 CVSS: 8.8 HIGH Product: MikroTik RouterOS Due Date: 2026-09-13

MikroTik RouterOS contains a missing authenticaion for critical function vulnerability which allows kernel memory disclosure and denial of service in the btest service.

GitHub PoC

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No GitHub PoC data.

FIRST EPSS

EPSS estimates the probability of exploitation in the next 30 days. Higher values indicate higher likelihood of real-world exploitation.

Timeline

CVE Stalker KEV MITRE GitHub FIRST (EPSS)

MITRE

CVSS

  • Score: 8.8
  • Severity: HIGH
  • Vector: 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

SSVC

  • Exploitation: active
  • Automatable: yes
  • Technical Impact: partial

References

Show Raw Data
Key Remaining Key Value
dataType CVE_RECORD
dataVersion 5.2
cveMetadata > cveId CVE-2026-67277
cveMetadata > assignerOrgId 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6
cveMetadata > state PUBLISHED
cveMetadata > assignerShortName CERT-PL
cveMetadata > dateReserved 2026-07-29T11:59:30.538Z
cveMetadata > datePublished 2026-09-05T20:00:56.614Z
cveMetadata > dateUpdated 2026-09-10T19:58:23.754Z
containers > cna > providerMetadata > orgId 4bb8329e-dd38-46c1-aafb-9bf32bcb93c6
containers > cna > providerMetadata > shortName CERT-PL
containers > cna > providerMetadata > dateUpdated 2026-09-05T20:39:44.166Z
containers > cna > title Kernel memory disclosure and denial of service in MikroTik RouterOS btest service
containers > cna > problemTypes > 0 > descriptions > 0 > lang en
containers > cna > problemTypes > 0 > descriptions > 0 > cweId CWE-306
containers > cna > problemTypes > 0 > descriptions > 0 > description CWE-306 Missing authentication for critical function
containers > cna > problemTypes > 0 > descriptions > 0 > type CWE
containers > cna > affected > 0 > vendor Mikrotik
containers > cna > affected > 0 > product RouterOS
containers > cna > affected > 0 > versions > 0 > status affected
containers > cna > affected > 0 > versions > 0 > version 7.24
containers > cna > affected > 0 > versions > 0 > lessThan 7.24.2
containers > cna > affected > 0 > versions > 0 > versionType custom
containers > cna > affected > 0 > versions > 1 > status affected
containers > cna > affected > 0 > versions > 1 > version 7.0.0
containers > cna > affected > 0 > versions > 1 > lessThan 7.23.4
containers > cna > affected > 0 > versions > 1 > versionType custom
containers > cna > affected > 0 > versions > 2 > status affected
containers > cna > affected > 0 > versions > 2 > version 6.0.0
containers > cna > affected > 0 > versions > 2 > lessThan 6.49.21
containers > cna > affected > 0 > versions > 2 > versionType custom
containers > cna > affected > 0 > defaultStatus unaffected
containers > cna > cpeApplicability > 0 > operator OR
containers > cna > cpeApplicability > 0 > nodes > 0 > operator OR
containers > cna > cpeApplicability > 0 > nodes > 0 > negate False
containers > cna > cpeApplicability > 0 > nodes > 0 > cpeMatch > 0 > vulnerable True
containers > cna > cpeApplicability > 0 > nodes > 0 > cpeMatch > 0 > criteria cpe:2.3:a:mikrotik:routeros:*:*:*:*:*:*:*:*
containers > cna > cpeApplicability > 0 > nodes > 0 > cpeMatch > 0 > versionStartIncluding 0.0.0
containers > cna > cpeApplicability > 0 > nodes > 0 > cpeMatch > 0 > versionEndExcluding 7.25.1
containers > cna > descriptions > 0 > lang en
containers > cna > descriptions > 0 > value 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)
containers > cna > descriptions > 0 > supportingMedia > 0 > type text/html
containers > cna > descriptions > 0 > supportingMedia > 0 > base64 False
containers > cna > descriptions > 0 > supportingMedia > 0 > value <div><div>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.</div></div><div>This issue was fixed in versions:&nbsp;6.49.21 (Long-term),&nbsp;7.23.4 (Long-term)&nbsp;and&nbsp;7.24.2 (Stable)</div>
containers > cna > references > 0 > url https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve
containers > cna > references > 0 > tags > 0 third-party-advisory
containers > cna > references > 1 > url https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/
containers > cna > references > 1 > tags > 0 technical-description
containers > cna > references > 2 > url https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/
containers > cna > references > 2 > tags > 0 exploit
containers > cna > references > 3 > url https://mikrotik.com/supportsec/september-2026-vulnerability/
containers > cna > references > 3 > tags > 0 vendor-advisory
containers > cna > references > 4 > url https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
containers > cna > references > 4 > tags > 0 release-notes
containers > cna > references > 5 > url https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
containers > cna > references > 5 > tags > 0 release-notes
containers > cna > references > 6 > url https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
containers > cna > references > 6 > tags > 0 release-notes
containers > cna > metrics > 0 > format CVSS
containers > cna > metrics > 0 > scenarios > 0 > lang en
containers > cna > metrics > 0 > scenarios > 0 > value GENERAL
containers > cna > metrics > 0 > cvssV4_0 > attackVector NETWORK
containers > cna > metrics > 0 > cvssV4_0 > attackComplexity LOW
containers > cna > metrics > 0 > cvssV4_0 > attackRequirements NONE
containers > cna > metrics > 0 > cvssV4_0 > privilegesRequired NONE
containers > cna > metrics > 0 > cvssV4_0 > userInteraction NONE
containers > cna > metrics > 0 > cvssV4_0 > vulnConfidentialityImpact LOW
containers > cna > metrics > 0 > cvssV4_0 > subConfidentialityImpact NONE
containers > cna > metrics > 0 > cvssV4_0 > vulnIntegrityImpact NONE
containers > cna > metrics > 0 > cvssV4_0 > subIntegrityImpact NONE
containers > cna > metrics > 0 > cvssV4_0 > vulnAvailabilityImpact HIGH
containers > cna > metrics > 0 > cvssV4_0 > subAvailabilityImpact NONE
containers > cna > metrics > 0 > cvssV4_0 > exploitMaturity NOT_DEFINED
containers > cna > metrics > 0 > cvssV4_0 > Safety NOT_DEFINED
containers > cna > metrics > 0 > cvssV4_0 > Automatable NOT_DEFINED
containers > cna > metrics > 0 > cvssV4_0 > Recovery NOT_DEFINED
containers > cna > metrics > 0 > cvssV4_0 > valueDensity NOT_DEFINED
containers > cna > metrics > 0 > cvssV4_0 > vulnerabilityResponseEffort NOT_DEFINED
containers > cna > metrics > 0 > cvssV4_0 > providerUrgency NOT_DEFINED
containers > cna > metrics > 0 > cvssV4_0 > version 4.0
containers > cna > metrics > 0 > cvssV4_0 > baseSeverity HIGH
containers > cna > metrics > 0 > cvssV4_0 > baseScore 8.8
containers > cna > metrics > 0 > cvssV4_0 > vectorString 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
containers > cna > credits > 0 > lang en
containers > cna > credits > 0 > value Sławomir Rozbicki (CERT.PL)
containers > cna > credits > 0 > type finder
containers > cna > source > discovery INTERNAL
containers > cna > x_generator > engine Vulnogram 1.0.3
containers > adp > 0 > metrics > 0 > other > type ssvc
containers > adp > 0 > metrics > 0 > other > content > id CVE-2026-67277
containers > adp > 0 > metrics > 0 > other > content > role CISA Coordinator
containers > adp > 0 > metrics > 0 > other > content > options > 0 > Exploitation active
containers > adp > 0 > metrics > 0 > other > content > options > 1 > Automatable yes
containers > adp > 0 > metrics > 0 > other > content > options > 2 > Technical Impact partial
containers > adp > 0 > metrics > 0 > other > content > version 2.0.3
containers > adp > 0 > metrics > 0 > other > content > timestamp 2026-09-10T19:48:06.780837Z
containers > adp > 0 > metrics > 1 > other > type kev
containers > adp > 0 > metrics > 1 > other > content > dateAdded 2026-09-10
containers > adp > 0 > metrics > 1 > other > content > reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67277
containers > adp > 0 > references > 0 > url https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2026-67277
containers > adp > 0 > references > 0 > tags > 0 government-resource
containers > adp > 0 > title CISA ADP Vulnrichment
containers > adp > 0 > providerMetadata > orgId 134c704f-9b21-4f2e-91b3-4a467353bcc0
containers > adp > 0 > providerMetadata > shortName CISA-ADP
containers > adp > 0 > providerMetadata > dateUpdated 2026-09-10T19:58:23.754Z
containers > adp > 0 > timeline > 0 > time 2026-09-10T00:00:00.000Z
containers > adp > 0 > timeline > 0 > lang en
containers > adp > 0 > timeline > 0 > value CVE-2026-67277 added to CISA KEV