Review reviewHigh

CVE-2026-33810

Go standard library crypto/x509, Cryostat 4 on RHEL 9, HawtIO HawtIO 4.4.0

When verifying a certificate chain containing excluded DNS constraints, these constraints are not correctly applied to wildcard DNS SANs which use a different case than the constraint. This only affects validation of otherwise trusted certificate chains, issued by a root CA in the VerifyOptions.Roots CertPool, or in the system certificate pool.

CVSS: 8.2
EPSS: 0.34%
CISA KEV: Not listed
Published: 2026.04.08

PRIORITY ASSESSMENT

Review review

The CVSS severity warrants an early asset and exposure review.

Known exploitationNot established by KEV

Exploit probability0.34%

Technical severityCVSS 8.2

Vulnerability overview

Affected product and versions

Product: Go standard library crypto/x509, Cryostat 4 on RHEL 9, HawtIO HawtIO 4.4.0
Affected versions: >= 1.26.0-0 < 1.26.2, >= 1.26.0 < 1.26.2
Fixed versions: 1.26.2

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Go standard library crypto/x509, Cryostat 4 on RHEL 9, HawtIO HawtIO 4.4.0 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
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:H/I:L/A:N
CWE: CWE-1289, CWE-295