How severe is CVE-2026-3978?

CVE-2026-3978 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-3978 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-3978?

CVE-2026-3978 affects Dlink Dir-513 Firmware. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-3978?

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.

Does CVE-2026-3978 have an EU (EUVD) identifier?

Yes. CVE-2026-3978 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11521.

When was CVE-2026-3978 published?

CVE-2026-3978 was published on 2026-03-12 and last updated on 2026-06-17.

CVE-2026-3978

CVE-2026-3978 is a high-severity vulnerability in Dlink Dir-513 Firmware with a CVSS 3.x base score of 8.8. 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-119.

Key facts

Severity: High (CVSS 3.x base score 8.8)
CVSS v2: 9.0
CVSS v4: 7.4
EPSS exploit prediction: 1% (49th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-11521
Weakness: CWE-119
Affected product: Dlink Dir-513 Firmware
Published: 2026-03-12
Last modified: 2026-06-17

Description

A vulnerability was detected in D-Link DIR-513 1.10. The impacted element is an unknown function of the file /goform/formEasySetupWizard3. The manipulation of the argument wan_connected results in stack-based buffer overflow. The attack can be launched remotely. The exploit is now public and may be used.

Frequently asked questions

What is CVE-2026-3978?: A vulnerability was detected in D-Link DIR-513 1.10. The impacted element is an unknown function of the file /goform/formEasySetupWizard3. The manipulation of the argument wan_connected results in stack-based buffer overflow. The attack can be launched remotely. The exploit is now public and may be used.
How severe is CVE-2026-3978?: CVE-2026-3978 has a CVSS 3.x base score of 8.8, rated high severity. It is exploitable over network with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-3978 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (49th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-3978?: CVE-2026-3978 affects Dlink Dir-513 Firmware. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-3978?: 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.
Does CVE-2026-3978 have an EU (EUVD) identifier?: Yes. CVE-2026-3978 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-11521.
When was CVE-2026-3978 published?: CVE-2026-3978 was published on 2026-03-12 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:o:dlink:dir-513_firmware:1.10:*:*:*:*:*:*:*

More vulnerabilities in Dlink Dir-513 Firmware

CVE-2025-70245 — Critical (CVSS 9.8): Stack buffer overflow vulnerability in D-Link DIR-513 v1.10 via the curTime parameter to goform/formSetWizardSelectMode.
CVE-2025-70233 — Critical (CVSS 9.8): Stack buffer overflow vulnerability in D-Link DIR-513 v1.10 via the curTime parameter to goform/formSetEnableWizard.
CVE-2025-70232 — Critical (CVSS 9.8): Stack buffer overflow vulnerability in D-Link DIR-513 v1.10 via the curTime parameter to goform/formSetMACFilter.
CVE-2025-70231 — Critical (CVSS 9.8): D-Link DIR-513 version 1.10 contains a critical-level vulnerability. When processing POST requests related to…
CVE-2025-70230 — Critical (CVSS 9.8): Stack buffer overflow vulnerability in D-Link DIR-513 v1.10 via the curTime parameter to goform/formSetDDNS.
CVE-2025-70229 — Critical (CVSS 9.8): Stack buffer overflow vulnerability in D-Link DIR-513 v1.10 via the curTime parameter to goform/formSchedule.

All CVEs affecting Dlink Dir-513 Firmware →

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