CVE-2026-3833: Red Hat Enterprise Linux 10 · Improper Handling of Case Sensitivity
Affects Red Hat Enterprise Linux 10Source CVE Database V5
Not known to be exploited · CVSS 6.5 Medium : upgrade Red Hat Enterprise Linux 10 to 3.8.13 when convenient.
Data as of 30 Oct 2026, 11:52 UTC
- EPSS
- 0.5% chance of exploitation in 30 days – higher than 46% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 3.8.13
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 30 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.
What to do
Upgrade gnutls to 3.8.13.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| gnutls | Affected
| Fixed in
|
AI-suggested
Red Hat has released security updates that fix this vulnerability in the GnuTLS library. Users of affected Red Hat products should apply the relevant GnuTLS package updates as provided in Red Hat security advisories RHSA-2026:13274 and RHSA-2026:20611. The advisories include updated GnuTLS packages for Red Hat Hardened Images and Red Hat Enterprise Linux 8. Applying these official updates fully mitigates the vulnerability. No additional mitigation steps are required beyond applying the vendor-provided patches.
Description
CVE-2026-3833 is a vulnerability in the GnuTLS library used by Red Hat Enterprise Linux 10 that arises from improper case-sensitive handling of name constraints in certificates. Specifically, GnuTLS performs case-sensitive comparisons of dNSName or rfc822Name labels in nameConstraints, which can be exploited by a remote attacker to bypass certificate validation policies. This flaw allows a crafted leaf certificate with differing case in the Subject Alternative Name to be accepted when it should be rejected, potentially leading to unauthorized access or information disclosure. Red Hat has released security updates addressing this issue in GnuTLS packages.
References
- access.redhat.com/errata/RHSA-2026:13274 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:20611 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:20612 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:20613 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26319 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:26409 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:29197 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:30004 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:30849 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:30850 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:32962 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:33125 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:41921 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:43575 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:57402 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:58981 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:59831 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:60019 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62409 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:62549 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65839 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:65851 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:67857 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:72502 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:74674 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:82304 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:82322 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:82347 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:82354 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:82372 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:82857 (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:82888 (opens in a new tab)
- access.redhat.com/security/cve/CVE-2026-3833 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2445763 (opens in a new tab)
- gitlab.com/gnutls/gnutls/-/issues/1803 (opens in a new tab)