CVE-2026-42012: Red Hat Enterprise Linux 10 · Improper Certificate Validation
Affects Red Hat Enterprise Linux 10Source CVE Database V5
Not known to be exploited · CVSS 7.1 High.
Data as of 26 Oct 2026, 08:30 UTC
- EPSS
- 0.3% chance of exploitation in 30 days – higher than 28% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:H/A:NExploitation evidence
Disclosed: evidence found.
CVE published 26 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| gnutls | Affected
| Fixed in– |
Description
A flaw was found in gnutls. A remote attacker could exploit this vulnerability by presenting a specially crafted certificate that contains Uniform Resource Identifier (URI) or Service (SRV) Subject Alternative Names (SANs). This could cause the certificate validation process to incorrectly fall back to checking DNS hostnames against the Common Name (CN), potentially allowing the attacker to spoof legitimate services or intercept sensitive information.
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/security/cve/CVE-2026-42012 (opens in a new tab)
- bugzilla.redhat.com/show_bug.cgi?id=2467441 (opens in a new tab)
- gnutls.org/security-new.html (opens in a new tab)
- access.redhat.com/errata/RHSA-2026:58981 (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)