CVE-2026-67276
Critical · CVSS 9.2Published 2026-09-05
CVSS
9.2
Critical
EPSS
—
exploit probability
Active Exploit
No
not yet listed
What is CVE-2026-67276?
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 was fixed in versions: 6.49.21 (Long-term), 7.23.4 (Long-term) and 7.24.2 (Stable)
CVSS Score Explained
CVSS 9.2 is Critical — the highest severity tier. Attackers can likely exploit this remotely with no authentication and cause full system compromise. Patch immediately.
EPSS Exploitation Probability
No EPSS score yet — model needs more data on this CVE.
References & Patches
- ›https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve
- PoChttps://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/
- PATCHhttps://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
- PATCHhttps://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
- PATCHhttps://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
- ›https://mikrotik.com/supportsec/september-2026-vulnerability/
- PATCHhttps://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/
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Recent CVEs
- CVE-2026-76160Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.—
- CVE-2026-76161Rejected reason: This CVE ID has been rejected or withdrawn by its CVE Numbering Authority.—
- CVE-2026-86150A security vulnerability has been detected in Tenda CP3 27.5.57.101. Impacted is an unknown function of the file custom-x/softap/hostapd. Such manipulation of the argument wpa_passphrase leads to hard-coded credentials. The attack can be launched remotely. The exploit has been disclosed publicly and may be used.2.0
- CVE-2026-86148A security flaw has been discovered in Tenda CP3 27.5.57.101. This vulnerability affects the function SystemAsh of the file Apis/system.c of the component Kylin. The manipulation of the argument AlarmVoiceURL results in os command injection. It is possible to launch the attack remotely.9.4
- CVE-2026-86149A weakness has been identified in Tenda CP3 27.5.57.101. This issue affects some unknown processing of the file Net/NetCheckPing.cpp. This manipulation of the argument interface_name/host causes os command injection. The attack can be initiated remotely.9.4
- CVE-2026-67277RouterOS 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)8.8