CVE-2026-67278

MEDIUMPre-NVD 6.36.3—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.3 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.2%, top 92% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, secondary
Trending — 3 sources updated this weekElevated
6.3EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.3Exploit: Elevated riskExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures across RSA-based services, including TLS/X.509 certificate validation and SSH host-key authentication. Because its trust store includes an e=3 root CA, an attacker controlling or redirecting an outbound RouterOS TLS connection can use the root’s public certificate - without its private key - to forge a trusted intermediate and issue certificates for arbitrary hostnames, enabling TLS server impersonation. The same permissive verification also undermines RSA-based SSH authentication.

This issue affects only 7.x branch was fixed in versions: 7.23.6 (Long-term) and 7.24.3 (Stable). Releases 7.23.4 and 7.24.2 included an incomplete fix.

CVSS v3
6.3
EG Score
6.3(medium)
EG Risk
44(Track)
EG Risk 44/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity63% × 45%
Exploitation40% × 40%
Automatability0% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
0%
EPSS %ILE
8%
KEV
Not listed

Published

September 5, 2026

Last Modified

September 17, 2026

Advisory Details (7)

Auto-updated Sep 5, 2026
⚠️ Active exploitation confirmed. Patch available.
generic

7.24.2 [stable] is released! - Announcements - MikroTik community forum

https://forum.mikrotik.com/t/7-24-2-stable-is-released/272800
generic

7.23.4 [long-term] is released! - Announcements - MikroTik community forum

https://forum.mikrotik.com/t/7-23-4-long-term-is-released/272801
generic

6.49.21 [long-term] is released! - Announcements - MikroTik community forum

https://forum.mikrotik.com/t/6-49-21-long-term-is-released/272802
generic

MikroTik · September 2026 vulnerability

https://mikrotik.com/supportsec/september-2026-vulnerability/
generic

Reversing MikroTik's Silent Patch: The RouterOS 7.23.4 Fix They Wouldn't Explain | Nick Pratley

https://npratley.net/reversing-mikrotiks-silent-patch-the-routeros-7-23-4-fix-they-wouldnt-explain/
generic🔴 Active Exploitation

Critical vulnerabilities in MikroTik RouterOS are being actively exploited. Immediate update recommended | CERT Polska

https://cert.pl/en/posts/2026/09/vulnerabilities-in-mikrotik-routeros-actively-exploited/
generic Patch Available

Vulnerabilities in Mikrotik RouterOS software | CERT Polska

https://cert.pl/en/posts/2026/09/mikrotik-routeros-cve

Vendor Advisories for CVE-2026-67278(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 18× in last 7d / 52× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-09-19 15:25 UTCEG score recompute
  2. 2026-09-19 15:24 UTCGHSA enrichment
  3. 2026-09-18 19:28 UTCEPSS rescore
  4. 2026-09-18 15:29 UTCEG score recompute
  5. 2026-09-18 15:29 UTCGHSA enrichment
  6. 2026-09-17 15:29 UTCEG score recompute
  7. 2026-09-17 15:29 UTCGHSA enrichment
  8. 2026-09-17 14:20 UTCEG score recompute
  9. 2026-09-17 14:19 UTCGHSA enrichment
  10. 2026-09-16 16:18 UTCEG score recompute
  11. 2026-09-16 16:17 UTCGHSA enrichment
  12. 2026-09-16 14:08 UTCEPSS rescore
  13. 2026-09-16 05:15 UTCEPSS rescore
  14. 2026-09-15 16:21 UTCEG score recompute
  15. 2026-09-15 16:21 UTCGHSA enrichment
  16. 2026-09-14 16:27 UTCEG score recompute
  17. 2026-09-14 16:27 UTCGHSA enrichment
  18. 2026-09-13 16:31 UTCGHSA enrichment
  19. 2026-09-12 16:37 UTCEG score recompute
  20. 2026-09-12 16:37 UTCGHSA enrichment
  21. 2026-09-11 16:43 UTCEG score recompute
  22. 2026-09-11 16:43 UTCGHSA enrichment
  23. 2026-09-11 14:53 UTCEPSS rescore
  24. 2026-09-11 09:37 UTCEPSS rescore
  25. 2026-09-10 16:49 UTCEG score recompute
Show 27 more
  1. 2026-09-10 16:49 UTCGHSA enrichment
  2. 2026-09-09 16:55 UTCEG score recompute
  3. 2026-09-09 16:55 UTCGHSA enrichment
  4. 2026-09-08 22:01 UTCEPSS rescore
  5. 2026-09-08 17:00 UTCEG score recompute
  6. 2026-09-08 17:00 UTCGHSA enrichment
  7. 2026-09-08 16:05 UTCEG score recompute
  8. 2026-09-08 16:05 UTCGHSA enrichment
  9. 2026-09-08 14:14 UTCEG score recompute
  10. 2026-09-08 14:14 UTCGHSA enrichment
  11. 2026-09-07 16:01 UTCEPSS rescore
  12. 2026-09-07 14:33 UTCEG score recompute
  13. 2026-09-07 14:32 UTCGHSA enrichment
  14. 2026-09-07 13:38 UTCEG score recompute
  15. 2026-09-07 13:37 UTCGHSA enrichment
  16. 2026-09-07 12:23 UTCEG score recompute
  17. 2026-09-07 12:22 UTCGHSA enrichment
  18. 2026-09-07 11:27 UTCEG score recompute
  19. 2026-09-07 11:27 UTCGHSA enrichment
  20. 2026-09-06 21:12 UTCEG score recompute
  21. 2026-09-06 21:12 UTCGHSA enrichment
  22. 2026-09-06 13:47 UTCEPSS rescore
  23. 2026-09-05 21:17 UTCEG score recompute
  24. 2026-09-05 20:45 UTCEG score recompute
  25. 2026-09-05 20:24 UTCEG score recompute
  26. 2026-09-05 20:05 UTCEG score recompute
  27. 2026-09-05 20:05 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-67278?
CVE-2026-67278 is a medium vulnerability published on September 5, 2026. MikroTik RouterOS accepts malformed RSA/PKCS#1 v1.5 signatures across RSA-based services, including TLS/X.509 certificate validation and SSH host-key authentication. Because its trust store includes an e=3 root CA, an attacker controlling or redirecting an outbound RouterOS TLS connection can use…
When was CVE-2026-67278 disclosed?
CVE-2026-67278 was first published in the National Vulnerability Database on September 5, 2026, with the most recent update on September 17, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-67278 actively exploited?
CVE-2026-67278 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 92.1% of all scored CVEs.
What is the CVSS score of CVE-2026-67278?
CVE-2026-67278 has a CVSS v3 base score of 6.3 (NVD).
How do I remediate CVE-2026-67278?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-67278, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

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