# CVE-2026-67276: MikroTik RouterOS SSH RSA public key comparison bypass

Source: https://junglewise.ai/threats/cve-2026-67276-routeros-does-not-compare-the-complete-rsa-public-key-when  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-05. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2026-67276 · Severity: high · CVSS 8.1 · Published 2026-09-05

MikroTik RouterOS, which manages network routing and connectivity, contains a flaw in its SSH authentication system that allows attackers to log in without the legitimate user's private key. An attacker who knows a user's public key modulus can craft a counterfeit key and gain remote command execution with the victim's privileges. This vulnerability is actively being exploited to compromise routers exposed to the internet.

Technologies: [MikroTik RouterOS](https://junglewise.ai/threats/technologies/routeros). Vendors: [MikroTik](https://junglewise.ai/threats/vendors/mikrotik).

## Quick answers

**Is CVE-2026-67276 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-67276 being exploited in the wild.

**How severe is CVE-2026-67276?** High severity, with a CVSS score of 8.1, published 5 September 2026.

**Which products and versions are affected?** MikroTik RouterOS 7.x branch; fixed in 7.23.4 (Long-term) and 7.24.2 (Stable).

**Is there a fix for CVE-2026-67276?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-67276 attacked?** It is attacked over the network.

**Am I affected by CVE-2026-67276?** Check whether you run MikroTik RouterOS at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The SSH server fails to validate the complete RSA public key during authentication, comparing only the key type and modulus while omitting verification of the exponent. An attacker supplies a key with exponent one, which produces valid signatures using the client-supplied key, bypassing authentication. Exploitation requires network access to SSH and knowledge of an authorized user's RSA modulus; no user interaction is needed.

## Affected products

- MikroTik RouterOS 7.x branch; fixed in 7.23.4 (Long-term) and 7.24.2 (Stable)

## Timeline

- 2026-09-05: disclosed
- 2026-09-05: exploited: actively exploited in the wild targeting internet-exposed devices

## References

- [https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve](https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve)
- [https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/](https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/)

## Related threats

- [MikroTik RouterOS session token replay authentication bypass in WebFig](https://junglewise.ai/threats/cve-2026-89035-mikrotik-routeros-through-7-24-5-contains-a-session-token-replay)
- [MikroTik RouterOS integer overflow in ipt_SAME module](https://junglewise.ai/threats/cve-2026-112158-a-weakness-has-been-identified-in-mikrotik-routeros-up-to-6-40-5)
- [MikroTik RouterOS WinBox incorrect authorization in authentication](https://junglewise.ai/threats/cve-2026-103903-an-incorrect-authorization-vulnerability-in-the-winbox)
- [MikroTik RouterOS integer underflow](https://junglewise.ai/threats/cve-2026-84411-mikrotik-routeros)
- [MikroTik RouterOS improper input validation in BGP labelled-VPN NLRI](https://junglewise.ai/threats/cve-2026-93345-mikrotik-routeros-before-7-25beta4-contains-an-improper-input)