← Vulnerability feed

Vulnerability record · CVE-2026-67276 · published 5 September 2026

CVE-2026-67276: Mikrotik routeros improper verification of cryptographic signature vulnerability

Mikrotik · Routeros

RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue affects only 7.x branch was fixed in versions: 7.23.4 (Long-term) and 7.24.2 (Stable)

9.2 CVSS 4.0 Critical EPSS 6.5% · top 6.5% CWE-347 · Improper verification of cryptographic signature
9.2CVSS 4.0 base score
6.5%EPSS exploitation probability, 30 days
NoNot in CISA KEV
1Affected product versions listed by NVD
6References, 1 tagged exploit
25 Sep 2026Last modified by NVD

Description

RouterOS does not compare the complete RSA public key when matching an SSH authentication request to an authorized user key, checking the key type and modulus but omitting the exponent. Because signature verification uses the client-supplied key, an attacker knowing an authorized RSA modulus can supply a key with exponent one, forge a valid signature, and open an SSH command channel as the target user without the private key.This issue affects only 7.x branch was fixed in versions: 7.23.4 (Long-term) and 7.24.2 (Stable)

CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/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:

Affected products

1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.

References

LinkTags
https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve Third Party Advisory
https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/ MitigationThird Party Advisory
https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801 Release Notes
https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800 Release Notes
https://mikrotik.com/supportsec/september-2026-vulnerability/ Vendor Advisory
https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/ ExploitThird Party Advisory

Track CVE-2026-67276 inside VULONE

Watch it alongside the ransomware crews, C2 infrastructure and forum chatter that reference it, query it through the API and pull it into your SIEM over TAXII.

Start free Open in platform

Related vulnerabilities

Same products first, then exploited flaws of the same weakness class.

9.8CVE-2018-7445MikroTik RouterOS SMB pre-auth buffer overflow enabling code executionMikroTik RouterOS contains a stack-based buffer overflow in its SMB service when handling NetBIOS session request messages. The overflow occurs befor…KEVEPSS 61%analysed9.2CVE-2026-86060MikroTik RouterOS SSH login argument injection privilege escalationRouterOS mishandles arguments in the SSH login path when a username begins with a prohibited character, allowing the trusted policy mask to be altere…KEVEPSS 1.8%analysed9.1CVE-2018-14847MikroTik RouterOS WinBox directory traversal allows file read and writeMikroTik RouterOS through 6.42 contains a directory traversal flaw in the WinBox interface. Unauthenticated remote attackers can read arbitrary files…KEVEPSS 96%analysed8.8CVE-2026-67277MikroTik RouterOS btest missing authentication leaks kernel memory and crashes kernelRouterOS accepts a "related" btest connection before the primary session is authenticated, letting an unauthenticated client start an IPv4 UDP test. …KEVEPSS 1.6%analysed6.9CVE-2026-67279Mikrotik routeros vulnerabilityRouterOS SSH enters the connection protocol after a client-requested rekey even though user authentication was never attempted, allowing an unauthent…KEVEPSS 1.0%9.8CVE-2022-45315Mikrotik routeros out-of-bounds read vulnerabilityMikrotik RouterOs before stable v7.6 was discovered to contain an out-of-bounds read in the snmp process. This vulnerability allows authenticated att…EPSS 1.3%9.8CVE-2017-20149Mikrotik routeros out-of-bounds write vulnerabilityThe Mikrotik RouterOS web server allows memory corruption in releases before Stable 6.38.5 and Long-term 6.37.5, aka Chimay-Red. A remote and unauthe…EPSS 2.0%9.8CVE-2022-34960Mikrotik routeros link following vulnerabilityThe container package in MikroTik RouterOS 7.4beta4 allows an attacker to create mount points pointing to symbolic links, which resolve to locations …EPSS 1.5%

Source: NIST National Vulnerability Database (record CVE-2026-67276), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.