6.5

CVE-2025-42611: mikrotik routeros Improper Certificate Validation

CVSS: 6.5v3.1MediumAwaiting analysis
Published 05-05-2026Last modified 05-05-2026

Vulnerability summary

CVE-2025-42611 is a medium (CVSS 6.5) Improper Certificate Validation vulnerability in mikrotik routeros. EPSS estimates a 0.19% chance of exploitation in the next 30 days, higher than 7.7% of scored vulnerabilities.

Overall risk
26/100
0100
Medium · default modelHow is this calculated?
CVSS score
6.5/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.19%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 05-05-2026
    PublishedVulnerability first disclosed.
  2. 05-05-2026
    Last modifiedVulnerability information updated.

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.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.19%

Chance of exploitation in the next 30 days

Percentile

8%

Versus all other CVEs

30-day change

0.00 pp

From 0.19% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.19%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Mikrotik1 product

1 vendor · 1 product

References

1 links