High 7.5Published Apr 7, 2026

CVE-2026-33810Case-sensitive excludedSubtrees name constraints cause Auth Bypass in crypto/x509

Updated under an hour ago (Oct 27, 2026, 1:00 PM ET)

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It affects Go standard library crypto/x509 and 59 other products. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

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Every CVE for Go standard library crypto/x509

Exploited in the last 30 days

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: 7.5 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Weakness (CWE): CWE-295, CWE-1289
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Go
NVD analysis: Modified
Record last updated: Sep 18, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Go standard library crypto/x509 go_standard_library:crypto_x509 (from the name)	from 1.26.0-0 before 1.26.2	CNA record
Red Hat Cryostat 4 on RHEL 9 redhat:cryostat	from 4.1.1-7 not affected	CISA ADP
Red Hat HawtIO HawtIO 4.4.0 redhat:apache_camel_hawtio	from operator-container not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 10 redhat:enterprise_linux	from 0:0.144.0-2.el10_2 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support redhat:enterprise_linux_eus	from 0:0.2.3-5.el10_0 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support redhat:rhel_aus	from 8060020260803064027.ad008a3a not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On redhat:rhel_eus_long_life	from 8060020260803064027.ad008a3a not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service redhat:rhel_tus	from 0:75-10.el8_8 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions redhat:rhel_e4s	from 0:75-10.el8_8 not affected	CISA ADP
Red Hat Red Hat Enterprise Linux 9.4 Extended Update Support redhat:rhel_eus	from 0:0.144.0-2.el9_4 not affected	CISA ADP
1–10 of 60

References

References

https://go.dev/cl/763763	patch
https://go.dev/issue/78332	issue-tracking
https://groups.google.com/g/golang-announce/c/0uYbvbPZRWU	mailing-list, release-notes
https://pkg.go.dev/vuln/GO-2026-4866	vendor-advisory
http://www.openwall.com/lists/oss-security/2026/04/19/4
http://www.openwall.com/lists/oss-security/2026/04/20/1
https://access.redhat.com/errata/RHSA-2026:10155
https://access.redhat.com/errata/RHSA-2026:10158
https://access.redhat.com/errata/RHSA-2026:13545
https://access.redhat.com/errata/RHSA-2026:14391
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.