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NVD / CVE Program· CNA CERT-PL

CVE-2026-67277: Kernel memory disclosure and denial of service in MikroTik RouterOS btest service

Noroxi assessment

Priority: This week (action score 65/100)

  • CISA has confirmed exploitation in the wild (Sep 10, 2026). Remediation deadline for US federal agencies: Sep 13, 2026.
  • Probability of exploitation in the next 30 days: 1.5% (FIRST EPSS); higher than 75.3% of all records.
  • Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
  • According to CISA the attack is automatable: targets can be found by mass scanning.
  • According to the record, no fixed version is available yet.

Don’t wait for the next maintenance window. Until a fix is released, restrict access to the affected component and follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

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)

HighCVSS 8.8 · v4.0KEVWeaponized No fix recorded
Published
Sep 5, 2026
Updated
Sep 11, 2026
EPSS
1.5% · 75th percentile

Report tools

JSON

Action score

65

This week

Don’t wait for the next maintenance window.

CVSS
35 / 40 · 8.8 / 10
CISA KEV
30 / 30 · Listed
EPSS
0 / 30 · 1.5%

CISA SSVC decision

Exploitation
active
Automatable
yes
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · CERT-PL
8.8
NVD has not scored this yet; the score shown is the CNA’s.

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Sep 10, 2026. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Sep 13, 2026.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-67277

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
mikrotikrouteros

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • mikrotik routeros6.0 and later · before 6.49.21
  • mikrotik routeros7.0 and later · before 7.23.4
  • mikrotik routeros7.24 and later · before 7.24.2

Versions reported by the vendor

Affected version ranges reported by the assigning authority (CERT-PL). Independent of NVD's CPE analysis and usually ahead of it.

  • Mikrotik RouterOS

    • 7.24 and later · before 7.24.2affected
    • 7.0.0 and later · before 7.23.4affected
    • 6.0.0 and later · before 6.49.21affected

Same product

mikrotik: all records

Other highest-scoring records for the same primary product.

  • CVE-2018-14847MikroTik RouterOS through 6.42 allows unauthenticated remote attackers to read arbitrary files and remote authenticated attackers to write aKEV
    95Now
  • CVE-2018-7445A buffer overflow was found in the MikroTik RouterOS SMB service when processing NetBIOS session request messages.KEV
    89Now
  • CVE-2026-86060SSH session privilege manipulation via a crafted username in Mikrotik RouterOSKEV
    68This week

Published before and after this one in the same product

  • ← EarlierCVE-2026-14227Jul 30, 2026 · Insufficient session expiration in MikroTik RouterOS
    27Monitor
  • ← EarlierCVE-2026-67276Sep 5, 2026 · SSH user impersonation possible in Mikrotik RouterOS
    39Monitor
  • Later →CVE-2026-67278Sep 5, 2026 · TLS server impersonation possible in Mikrotik RouterOS
    25Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

  1. Published
  2. CISA KEV+4 d
  3. TodayNov 6, 2026+62 d
EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

—

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-890219 days apartMikroTik RouterOS Path Traversal via Container OCI/tar Image Extraction
    27Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
X

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS 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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

nvd-secondary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

ts
// Added for the support teamapp.post("/maintenance/reset", resetDevice);

Fixed

ts
if (config.maintenanceEnabled) {  app.post(    "/maintenance/reset",    requireSession, requireRole("admin"), resetDevice  );}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

ATT&CK techniques

—

Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

Show all references (6 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records