Skip to content
Weekly Signal
Live intelligence Updated 20 Aug 2026 · 23:29 UTC

GNU, Redhat · Gnutls, Enterprise Linux, Hardened Images +1 more

CVE-2026-3833

A flaw was found in gnutls. This vulnerability occurs because gnutls performs case-sensitive comparisons of `nameConstraints` labels, specifically...

Recommended action

Handle this through the normal risk-based patching cycle while monitoring for change. Red Hat Security advisory RHSA-2026:20611

View response plan
CVSS7.4
EPSS0.6%
KEVNo
ExploitationNone
RemediationNot yet verified ↓

Assessment

Why it matters

EPSS is 0.6%; technical severity is CVSS 7.4.

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.

Who should care

  • Teams operating Gnutls, Enterprise Linux, Hardened Images +1 more
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether Gnutls, Enterprise Linux, Hardened Images +1 more is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Red Hat Security advisory RHSA-2026:20611
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Treatment intelligence

Remediation intelligence

Not yet verified

Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.

Verification noteAutomated link verification has not completed for this guidance yet.

Advisory

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
CWE
CWE-178
Affected versions
GNU Gnutls (Version -); Redhat Enterprise Linux (Version 6.0 | Version 7.0 | Version 8.0 | Version 9.0); Redhat Hardened Images (Version -); Redhat Openshift Container Platform (Version 4.0)
Fixed versions
No explicit fixed version is currently recorded.
Published
30 April 2026
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. CVE published
  2. Latest EPSS score: 0.6%
  3. Signal calculated at 12

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.