CVE-2025-42611: Mikrotik RouterOS · Improper Certificate Validation
Affects Mikrotik RouterOSSource CVE Database V5
Not known to be exploited · CVSS 6.5 Medium.
Data as of 1 Nov 2026, 22:57 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 5 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 1 Nov 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| MikrotikRouterOS | Affected
| Fixed in– |
AI-suggested
Until an official fix is released, users should be cautious about the trust relationships configured in the system-wide certificate store and consider limiting the certificate authorities trusted by RouterOS services if possible.
Description
RouterOS provides various services that rely on correct verification of client and server certificates to secure confidentiality and integrity of communications. This includes OpenVPN, CAPsMAN, Dot1x (802.1X), among others. The vulnerability lies in shared certificate validation logic which uses the system certificate store that is shared and equally trusted by all system services. This causes confusion of scope, allowing any certificate authority present in the system-wide trust store to be trusted in any context (with some exceptions), allowing partial or full authentication bypass in CAPsMAN, OpenVPN, Dot1X and potentially others.