How severe is CVE-2026-6731?

CVE-2026-6731 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-2026-6731 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-6731?

CVE-2026-6731 affects Wolfssl. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-6731?

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-2026-6731 have an EU (EUVD) identifier?

Yes. CVE-2026-6731 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39555.

When was CVE-2026-6731 published?

CVE-2026-6731 was published on 2026-06-25 and last updated on 2026-06-27.

CVE-2026-6731

CVE-2026-6731 is a high-severity vulnerability in Wolfssl 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-295.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v4: 6.0
EPSS exploit prediction: 0% (3rd percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-39555
Weakness: CWE-295
Affected product: Wolfssl
Published: 2026-06-25
Last modified: 2026-06-27

Description

X.509 name constraint bypass via the Subject Common Name when treated as a DNS-type name. A certificate whose Subject CN violates an issuing CA's DNS name constraints could be accepted.

Frequently asked questions

What is CVE-2026-6731?: X.509 name constraint bypass via the Subject Common Name when treated as a DNS-type name. A certificate whose Subject CN violates an issuing CA's DNS name constraints could be accepted.
How severe is CVE-2026-6731?: CVE-2026-6731 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-2026-6731 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (3rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-6731?: CVE-2026-6731 affects Wolfssl. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-6731?: 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-2026-6731 have an EU (EUVD) identifier?: Yes. CVE-2026-6731 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-39555.
When was CVE-2026-6731 published?: CVE-2026-6731 was published on 2026-06-25 and last updated on 2026-06-27.

References

Affected products (1)

cpe:2.3:a:wolfssl:wolfssl:*:*:*:*:*:*:*:*

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