CVE-2026-271377.5HighCWE-295

CVE-2026-27137: Incorrect enforcement of email constraints in crypto/x509

Go standard library · crypto/x509

Vendor fix available · Affected: Go standard library crypto/x509 · Exploitation: unlikely (under 1%)

Not in CyberSIXT coverage yet: no article names this CVE. This page shows the public record.

0.7%probability of exploitation in the next 30 days

52nd percentile

050100

Higher than 52% of scored CVEs

7.5HighCVSS 3.1

LowMediumHighCrit.

DescriptionCVE.org

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.

Affected products1

From the CVE record. A product or version that is not listed is unknown, not unaffected.

Go standard library · crypto/x509from 1.26.0-0 before 1.26.1

On the Atlas

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Exploitation: Unlikely (under 1%). EPSS under 1%, or no score yet.
CISA KEV: Not listed
Public check: No public nuclei template
Weakness: Improper Certificate Validation · Cryptography
Vendor: Go standard library
Published: March 2026
Band: Unlikely (under 1%), March 2026

CoverageNo articles yet

No CyberSIXT article names CVE-2026-27137 yet, so there is no coverage timeline, action brief or change log for it. Everything on this page comes from the public CVE record, CISA KEV, EPSS and the nuclei template index. Search the archive or see the CVEs in the news.

References

28 more references are in the CVE record.