CVE-2026-3833

Summary

A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of nameConstraints labels, specifically for dNSName (DNS) or rfc822Name (email) constraints within excludedSubtrees or permittedSubtrees. A remote attacker can exploit this by crafting a leaf certificate with casing differences in the Subject Alternative Name (SAN), leading to a policy bypass where a certificate that should be rejected is instead accepted. This could result in unauthorized access or information disclosure.

Affected Software

VendorProductVersion RangeStatus
0 < 3.8.13affected
Red HatRed Hat Enterprise Linux 100:3.8.10-4.el10_2 < *unaffected
Red HatRed Hat Enterprise Linux 10.0 Extended Update Support0:3.8.9-9.el10_0.19 < *unaffected
Red HatRed Hat Enterprise Linux 80:3.6.16-8.el8_10.6 < *unaffected
Red HatRed Hat Enterprise Linux 80:3.6.16-8.el8_10.6 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support0:3.6.14-10.el8_4.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support0:4.13-3.el8_4.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On0:3.6.14-10.el8_4.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On0:4.13-3.el8_4.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support0:3.6.16-5.el8_6.5 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support0:4.13-3.el8_6.2 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On0:3.6.16-5.el8_6.5 < *unaffected
Red HatRed Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On0:4.13-3.el8_6.2 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Service0:3.6.16-7.el8_8.4 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Telecommunications Update Service0:4.13-4.el8_8.1 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutions0:3.6.16-7.el8_8.4 < *unaffected
Red HatRed Hat Enterprise Linux 8.8 Update Services for SAP Solutions0:4.13-4.el8_8.1 < *unaffected
Red HatRed Hat Enterprise Linux 90:3.8.10-4.el9_8 < *unaffected
Red HatRed Hat Enterprise Linux 90:3.8.10-4.el9_8 < *unaffected
Red HatRed Hat Enterprise Linux 9.4 Update Services for SAP Solutions0:3.8.3-4.el9_4.6 < *unaffected
Red HatRed Hat Enterprise Linux 9.6 Extended Update Support0:3.8.3-6.el9_6.4 < *unaffected
Red HatRed Hat Discovery 21782159791 < *unaffected
Red HatRed Hat Discovery 21782166952 < *unaffected
Red HatRed Hat Hardened Images3.8.13-1.hum1 < *unaffected
Red HatRed Hat Update Infrastructure 51781525684 < *unaffected
Red HatRed Hat Update Infrastructure 51781525671 < *unaffected
Red HatRed Hat Update Infrastructure 51781525693 < *unaffected
Red HatRed Hat Update Infrastructure 51781525739 < *unaffected

Weaknesses

  • CWE-178: Improper Handling of Case Sensitivity

Workarounds

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: yes
    • Technical Impact: partial

Additional References

References