Improper Handling of Case Sensitivity Affecting std/crypto/x509 package, versions >=1.26.0-0 <1.26.2
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published8 Apr 2026
- disclosed7 Apr 2026
- creditRiyas, k1rnt, @1seal
Introduced: 7 Apr 2026
CVE-2026-33810 (opens in a new tab)How to fix?
Upgrade std/crypto/x509 to version 1.26.2 or higher.
Overview
std/crypto/x509 is a Go standard library package std/crypto/x509
Affected versions of this package are vulnerable to Improper Handling of Case Sensitivity.
Go Vulnerability Report:
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.