Vulnerability-Lookup

GHSA-6RGH-57XM-37V8

Vulnerability from github – Published: 2026-04-30 18:30 – Updated: 2026-05-03 21:32

Details

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.

Severity ?

6.5 (Medium)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

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{
  "affected": [],
  "aliases": [
    "CVE-2026-3833"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-178"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-04-30T18:16:30Z",
    "severity": "MODERATE"
  },
  "details": "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.",
  "id": "GHSA-6rgh-57xm-37v8",
  "modified": "2026-05-03T21:32:55Z",
  "published": "2026-04-30T18:30:33Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-3833"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/errata/RHSA-2026:13274"
    },
    {
      "type": "WEB",
      "url": "https://access.redhat.com/security/cve/CVE-2026-3833"
    },
    {
      "type": "WEB",
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2445763"
    },
    {
      "type": "WEB",
      "url": "https://gitlab.com/gnutls/gnutls/-/issues/1803"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2026-3833 (GCVE-0-2026-3833)

Vulnerability from cvelistv5 – Published: 2026-04-30 17:37 – Updated: 2026-05-04 12:49

Title

Gnutls: gnutls: policy bypass due to case-sensitive nameconstraints comparison

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.

Severity ?

6.5 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

CWE

CWE-178 - Improper Handling of Case Sensitivity

Assigner

redhat

References

4 references

URL	Tags
https://access.redhat.com/errata/RHSA-2026:13274	vendor-advisoryx_refsource_REDHAT
https://access.redhat.com/security/cve/CVE-2026-3833	vdb-entryx_refsource_REDHAT
https://bugzilla.redhat.com/show_bug.cgi?id=2445763	issue-trackingx_refsource_REDHAT
https://gitlab.com/gnutls/gnutls/-/issues/1803

Impacted products

8 products

Vendor	Product	Version
		Affected: 0 , < 3.8.13 (semver)
Red Hat	Red Hat Hardened Images	Unaffected: 3.8.13-1.hum1 , < * (rpm) cpe:/a:redhat:hummingbird:1
Red Hat	Red Hat Enterprise Linux 10	cpe:/o:redhat:enterprise_linux:10
Red Hat	Red Hat Enterprise Linux 6	cpe:/o:redhat:enterprise_linux:6
Red Hat	Red Hat Enterprise Linux 7	cpe:/o:redhat:enterprise_linux:7
Red Hat	Red Hat Enterprise Linux 8	cpe:/o:redhat:enterprise_linux:8
Red Hat	Red Hat Enterprise Linux 9	cpe:/o:redhat:enterprise_linux:9
Red Hat	Red Hat OpenShift Container Platform 4	cpe:/a:redhat:openshift:4

Date Public ?

2026-04-30 17:26

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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-6RGH-57XM-37V8

CVE-2026-3833 (GCVE-0-2026-3833)

Tags

Sightings

Nomenclature