How severe is CVE-2019-3979?

CVE-2019-3979 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.

Is CVE-2019-3979 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2019-3979?

CVE-2019-3979 primarily affects Mikrotik Routeros. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2019-3979?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2019-3979 published?

CVE-2019-3979 was published on 2019-10-29 and last updated on 2026-06-17.

CVE-2019-3979

CVE-2019-3979 is a high-severity vulnerability in Mikrotik Routeros with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-345.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 1% (56th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-345
Affected product: Mikrotik Routeros
Published: 2019-10-29
Last modified: 2026-06-17

Description

RouterOS versions 6.45.6 Stable, 6.44.5 Long-term, and below are vulnerable to a DNS unrelated data attack. The router adds all A records to its DNS cache even when the records are unrelated to the domain that was queried. Therefore, a remote attacker controlled DNS server can poison the router's DNS cache via malicious responses with additional and untrue records.

Frequently asked questions

What is CVE-2019-3979?: RouterOS versions 6.45.6 Stable, 6.44.5 Long-term, and below are vulnerable to a DNS unrelated data attack. The router adds all A records to its DNS cache even when the records are unrelated to the domain that was queried. Therefore, a remote attacker controlled DNS server can poison the router's DNS cache via malicious responses with additional and untrue records.
How severe is CVE-2019-3979?: CVE-2019-3979 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability none.
Is CVE-2019-3979 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (56th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-3979?: CVE-2019-3979 primarily affects Mikrotik Routeros. In total, 2 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-3979?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-3979 published?: CVE-2019-3979 was published on 2019-10-29 and last updated on 2026-06-17.

References

https://www.tenable.com/security/research/tra-2019-46

Affected products (2)

cpe:2.3:o:mikrotik:routeros:*:*:*:*:ltr:*:*:*
cpe:2.3:o:mikrotik:routeros:*:*:*:*:-:*:*:*

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CVE-2026-50195 — Critical (CVSS 9.9): containerd is an open-source container runtime. Versions prior to 2.3.2, 2.2.5 and 2.1.9 contain a vulnerability in the…
CVE-2022-36130 — Critical (CVSS 9.9): HashiCorp Boundary up to 0.10.1 did not properly perform data integrity checks to ensure the resources were associated…
CVE-2026-50214 — Critical (CVSS 9.8): The /v1/Plan service relies entirely on a shared global API token for full administrative management, allowing…
CVE-2025-15385 — Critical (CVSS 9.8): Insufficient Verification of Data Authenticity vulnerability in TECNO Mobile com.Afmobi.Boomplayer allows…

Browse all CWE-345 (Insufficient Verification of Data Authenticity) vulnerabilities →

Threat intelligence

Threat-intel indicators referencing this CVE:

35.130.111.146 (ipv4-addr)
35.130.111.98 (ipv4-addr)
27.110.176.222 (ipv4-addr)