Mikrotik RouterOS up to 6.49.20/7.23.3/7.24.1 signature verification

Summaryinfo

A vulnerability, which was classified as very critical, has been found in Mikrotik RouterOS up to 6.49.20/7.23.3/7.24.1. Affected is an unknown function. The manipulation leads to signature verification. This vulnerability is referenced as CVE-2026-67276. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability was found in Mikrotik RouterOS up to 6.49.20/7.23.3/7.24.1. It has been rated as very critical. This issue affects an unknown functionality. The manipulation with an unknown input leads to a signature verification vulnerability. Using CWE to declare the problem leads to CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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 (Lont-term), 7.23.4 (Lont-term) and 7.24.2 (Stable)

The advisory is shared at cert.pl. The identification of this vulnerability is CVE-2026-67276 since 07/29/2026. The exploitation is known to be easy. The attack may be initiated remotely. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/06/2026).

Upgrading to version 6.49.21, 7.23.4 or 7.24.2 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-72024). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

Type

• Router Operating System

Vendor

• Mikrotik

Name

• RouterOS

Version

• 6.49.0
• 6.49.1
• 6.49.2
• 6.49.3
• 6.49.4
• 6.49.5
• 6.49.6
• 6.49.7
• 6.49.8
• 6.49.9
• 6.49.10
• 6.49.11
• 6.49.12
• 6.49.13
• 6.49.14
• 6.49.15
• 6.49.16
• 6.49.17
• 6.49.18
• 6.49.19
• 6.49.20
• 7.23.0
• 7.23.1
• 7.23.2
• 7.23.3
• 7.24.0
• 7.24.1

License

• commercial

CPE 2.3info

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CPE 2.2info

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If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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