Review reviewHigh

CVE-2026-27137

Go standard library crypto/x509, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support

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.

CVSS
7.5
EPSS
0.61%
45.6% percentile
CISA KEV
Not listed
Published
2026.03.07
PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV
Exploit probability0.61%
Technical severityCVSS 7.5

Vulnerability overview

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 product and versions

Product
Go standard library crypto/x509, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support
Affected versions
>= 1.26.0-0 < 1.26.1, 1.26.0
Fixed versions
No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide
  1. 1
    Identify

    Confirm that Go standard library crypto/x509, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 10.0 Extended Update Support and an affected version are present.

  2. 2
    Prioritize

    Combine exploitation signals with asset exposure and business criticality.

  3. 3
    Remediate

    Follow the vendor advisory or supported update path and preserve rollback options.

  4. 4
    Verify

    Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CWE
CWE-295