Riskcovery

CVE-2026-33810

Case-sensitive excludedSubtrees name constraints cause Auth Bypass in crypto/x509

State
Published
Severity
7.5 High
Published
Apr 8, 2026
Updated
Sep 18, 2026
Reserved
Mar 23, 2026

Read the record on cve.org

Description

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.

Scores

CVSSScoreVectorSource
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:NCISA-ADP
3.18.8 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:Lredhat-SADP

Weaknesses

  • CWE-1289 Improper Validation of Unsafe Equivalence in Input

Affected Products

ProductVersions
crypto/x509Go standard library
  • 1.26.0-0 to before 1.26.2Affected

References

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