CVE-2026-42013: Red Hat Cert Manager Support For Red Hat Openshift Release 1.20

High severity, CVSS 8.2. EPSS: 0.6% chance of exploitation in the next 30 days.

A flaw was found in gnutls. When validating certificates, an oversized Subject Alternative Name (SAN) could cause the validation process to incorrectly fall back to checking the Common Name (CN) field. This could allow a remote attacker to bypass proper certificate validation, potentially leading to spoofing or man-in-the-middle attacks.

Affected products

Red Hat Cert Manager Support For Red Hat Openshift Release 1.20: before 1790598593 (fixed in 1790598593)
Red Hat Red Hat Discovery 2: before 1782159791 (fixed in 1782159791); before 1782166952 (fixed in 1782166952)
Red Hat Red Hat Enterprise Linux 10: before 0:3.8.10-4.el10_2 (fixed in 0:3.8.10-4.el10_2)
Red Hat Red Hat Enterprise Linux 10.0 Extended Update Support: before 0:3.8.9-9.el10_0.19 (fixed in 0:3.8.9-9.el10_0.19)
Red Hat Red Hat Enterprise Linux 6
Red Hat Red Hat Enterprise Linux 7 Extended Lifecycle Support: before 0:3.3.29-9.el7_9.2 (fixed in 0:3.3.29-9.el7_9.2)
Red Hat Red Hat Enterprise Linux 8: before 0:3.6.16-8.el8_10.6 (fixed in 0:3.6.16-8.el8_10.6)
Red Hat Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support: before 0:3.6.14-10.el8_4.1 (fixed in 0:3.6.14-10.el8_4.1); before 0:4.13-3.el8_4.1 (fixed in 0:4.13-3.el8_4.1)
Red Hat Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On: before 0:3.6.14-10.el8_4.1 (fixed in 0:3.6.14-10.el8_4.1); before 0:4.13-3.el8_4.1 (fixed in 0:4.13-3.el8_4.1)
Red Hat Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support: before 0:3.6.16-5.el8_6.5 (fixed in 0:3.6.16-5.el8_6.5); before 0:4.13-3.el8_6.2 (fixed in 0:4.13-3.el8_6.2)
Red Hat Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On: before 0:3.6.16-5.el8_6.5 (fixed in 0:3.6.16-5.el8_6.5); before 0:4.13-3.el8_6.2 (fixed in 0:4.13-3.el8_6.2)
Red Hat Red Hat Enterprise Linux 8.8 Telecommunications Update Service: before 0:3.6.16-7.el8_8.4 (fixed in 0:3.6.16-7.el8_8.4); before 0:4.13-4.el8_8.1 (fixed in 0:4.13-4.el8_8.1)
Red Hat Red Hat Enterprise Linux 8.8 Update Services For SAP Solutions: before 0:3.6.16-7.el8_8.4 (fixed in 0:3.6.16-7.el8_8.4); before 0:4.13-4.el8_8.1 (fixed in 0:4.13-4.el8_8.1)
Red Hat Red Hat Enterprise Linux 9: before 0:3.8.10-4.el9_8 (fixed in 0:3.8.10-4.el9_8)
Red Hat Red Hat Enterprise Linux 9.2 Update Services For SAP Solutions: before 0:3.7.6-21.el9_2.7 (fixed in 0:3.7.6-21.el9_2.7)
Red Hat Red Hat Enterprise Linux 9.4 Update Services For SAP Solutions: before 0:3.8.3-4.el9_4.6 (fixed in 0:3.8.3-4.el9_4.6)
Red Hat Red Hat Enterprise Linux 9.6 Extended Update Support: before 0:3.8.3-6.el9_6.4 (fixed in 0:3.8.3-6.el9_6.4)
Red Hat Red Hat Hardened Images: before 3.8.13-1.hum1 (fixed in 3.8.13-1.hum1)
Red Hat Red Hat Openshift Ai 3.4: before 1790703542 (fixed in 1790703542)
Red Hat Red Hat Openshift Container Platform 4
Red Hat Red Hat Openshift Container Platform 4.12: before 412.86.202608241157-0 (fixed in 412.86.202608241157-0)
Red Hat Red Hat Openshift Container Platform 4.16: before 416.94.202608150307-0 (fixed in 416.94.202608150307-0)
Red Hat Red Hat Openshift Container Platform 4.17: before 417.94.202608250221-0 (fixed in 417.94.202608250221-0)
Red Hat Red Hat Openshift Container Platform 4.18: before 418.94.202608142238-0 (fixed in 418.94.202608142238-0)
Red Hat Red Hat Openshift Container Platform 4.19: before 4.19.9.6.202607151909-0 (fixed in 4.19.9.6.202607151909-0)
and 1 more

Published 2026-05-26. Last modified 2026-10-10.