How severe is CVE-2026-27137?

CVE-2026-27137 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 none, and availability high.

Is CVE-2026-27137 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-27137?

CVE-2026-27137 affects Golang Go. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-27137?

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-2026-27137 have an EU (EUVD) identifier?

Yes. CVE-2026-27137 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10085.

When was CVE-2026-27137 published?

CVE-2026-27137 was published on 2026-03-06 and last updated on 2026-07-08.

CVE-2026-27137

CVE-2026-27137 is a high-severity vulnerability in Golang Go 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)
EPSS exploit prediction: 1% (45th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-10085
Weakness: CWE-295
Affected product: Golang Go
Published: 2026-03-06
Last modified: 2026-07-08

Description

When verifying a certificate chain which contains a certificate containing multiple email address constraints which share common local portions but different domain portions, these constraints will not be properly applied, and only the last constraint will be considered.

Frequently asked questions

What is CVE-2026-27137?: When verifying a certificate chain which contains a certificate containing multiple email address constraints which share common local portions but different domain portions, these constraints will not be properly applied, and only the last constraint will be considered.
How severe is CVE-2026-27137?: CVE-2026-27137 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 none, and availability high.
Is CVE-2026-27137 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (45th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-27137?: CVE-2026-27137 affects Golang Go. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-27137?: 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-2026-27137 have an EU (EUVD) identifier?: Yes. CVE-2026-27137 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-10085.
When was CVE-2026-27137 published?: CVE-2026-27137 was published on 2026-03-06 and last updated on 2026-07-08.

References

Affected products (1)

cpe:2.3:a:golang:go:1.26.0:*:*:*:*:*:*:*

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