RLSA-2026:19145

Synopsis

Important: krb5 security update

Description

Kerberos is a network authentication system, which can improve the security of your network by eliminating the insecure practice of sending passwords over the network in unencrypted form. It allows clients and servers to authenticate to each other with the help of a trusted third party, the Kerberos key distribution center (KDC).

Security Fix(es):

* krb5: MIT Kerberos 5 (krb5): Denial of Service via integer underflow and out-of-bounds read (CVE-2026-40356)

* krb5: MIT Kerberos 5: Denial of Service via NULL pointer dereference in NegoEx mechanism (CVE-2026-40355)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Affected products

Rocky Linux 10 aarch64 Rocky Linux 10 ppc64le Rocky Linux 10 riscv64 Rocky Linux 10 s390x Rocky Linux 10 x86_64

Fixes

2463370 2463368

CVEs

CVE-2026-40355 CVE-2026-40356

Affected packages

Rocky Linux 10 x86_64 - AppStream

krb5-devel-0:1.21.3-10.el10_2.x86_64.rpm

Rocky Linux 10 aarch64 - BaseOS

krb5-server-debuginfo-0:1.21.3-10.el10_2.aarch64.rpm krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.aarch64.rpm krb5-debugsource-0:1.21.3-10.el10_2.aarch64.rpm krb5-debuginfo-0:1.21.3-10.el10_2.aarch64.rpm krb5-server-ldap-0:1.21.3-10.el10_2.aarch64.rpm krb5-pkinit-0:1.21.3-10.el10_2.aarch64.rpm libkadm5-0:1.21.3-10.el10_2.aarch64.rpm krb5-0:1.21.3-10.el10_2.src.rpm krb5-libs-0:1.21.3-10.el10_2.aarch64.rpm krb5-xrealmauthz-debuginfo-0:1.21.3-10.el10_2.aarch64.rpm krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.aarch64.rpm krb5-xrealmauthz-0:1.21.3-10.el10_2.aarch64.rpm krb5-workstation-debuginfo-0:1.21.3-10.el10_2.aarch64.rpm krb5-libs-debuginfo-0:1.21.3-10.el10_2.aarch64.rpm krb5-workstation-0:1.21.3-10.el10_2.aarch64.rpm krb5-server-0:1.21.3-10.el10_2.aarch64.rpm libkadm5-debuginfo-0:1.21.3-10.el10_2.aarch64.rpm

Rocky Linux 10 ppc64le - BaseOS

krb5-libs-debuginfo-0:1.21.3-10.el10_2.ppc64le.rpm libkadm5-debuginfo-0:1.21.3-10.el10_2.ppc64le.rpm krb5-xrealmauthz-0:1.21.3-10.el10_2.ppc64le.rpm libkadm5-0:1.21.3-10.el10_2.ppc64le.rpm krb5-xrealmauthz-debuginfo-0:1.21.3-10.el10_2.ppc64le.rpm krb5-debuginfo-0:1.21.3-10.el10_2.ppc64le.rpm krb5-pkinit-0:1.21.3-10.el10_2.ppc64le.rpm krb5-0:1.21.3-10.el10_2.src.rpm krb5-server-ldap-0:1.21.3-10.el10_2.ppc64le.rpm krb5-debugsource-0:1.21.3-10.el10_2.ppc64le.rpm krb5-server-debuginfo-0:1.21.3-10.el10_2.ppc64le.rpm krb5-libs-0:1.21.3-10.el10_2.ppc64le.rpm krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.ppc64le.rpm krb5-workstation-debuginfo-0:1.21.3-10.el10_2.ppc64le.rpm krb5-workstation-0:1.21.3-10.el10_2.ppc64le.rpm krb5-server-0:1.21.3-10.el10_2.ppc64le.rpm krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.ppc64le.rpm

Rocky Linux 10 s390x - AppStream

krb5-devel-0:1.21.3-10.el10_2.s390x.rpm

Rocky Linux 10 x86_64 - BaseOS

krb5-xrealmauthz-debuginfo-0:1.21.3-10.el10_2.x86_64.rpm libkadm5-0:1.21.3-10.el10_2.x86_64.rpm krb5-libs-0:1.21.3-10.el10_2.x86_64.rpm krb5-server-debuginfo-0:1.21.3-10.el10_2.x86_64.rpm krb5-pkinit-0:1.21.3-10.el10_2.x86_64.rpm krb5-libs-debuginfo-0:1.21.3-10.el10_2.x86_64.rpm libkadm5-debuginfo-0:1.21.3-10.el10_2.x86_64.rpm krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.x86_64.rpm krb5-debugsource-0:1.21.3-10.el10_2.x86_64.rpm krb5-0:1.21.3-10.el10_2.src.rpm krb5-server-ldap-0:1.21.3-10.el10_2.x86_64.rpm krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.x86_64.rpm krb5-workstation-0:1.21.3-10.el10_2.x86_64.rpm krb5-server-0:1.21.3-10.el10_2.x86_64.rpm krb5-debuginfo-0:1.21.3-10.el10_2.x86_64.rpm krb5-workstation-debuginfo-0:1.21.3-10.el10_2.x86_64.rpm krb5-xrealmauthz-0:1.21.3-10.el10_2.x86_64.rpm

Rocky Linux 10 s390x - BaseOS

krb5-libs-0:1.21.3-10.el10_2.s390x.rpm libkadm5-debuginfo-0:1.21.3-10.el10_2.s390x.rpm krb5-libs-debuginfo-0:1.21.3-10.el10_2.s390x.rpm krb5-xrealmauthz-0:1.21.3-10.el10_2.s390x.rpm krb5-debugsource-0:1.21.3-10.el10_2.s390x.rpm krb5-server-ldap-0:1.21.3-10.el10_2.s390x.rpm krb5-pkinit-0:1.21.3-10.el10_2.s390x.rpm krb5-debuginfo-0:1.21.3-10.el10_2.s390x.rpm krb5-server-ldap-debuginfo-0:1.21.3-10.el10_2.s390x.rpm krb5-server-0:1.21.3-10.el10_2.s390x.rpm krb5-0:1.21.3-10.el10_2.src.rpm krb5-pkinit-debuginfo-0:1.21.3-10.el10_2.s390x.rpm krb5-workstation-debuginfo-0:1.21.3-10.el10_2.s390x.rpm libkadm5-0:1.21.3-10.el10_2.s390x.rpm krb5-workstation-0:1.21.3-10.el10_2.s390x.rpm krb5-xrealmauthz-debuginfo-0:1.21.3-10.el10_2.s390x.rpm krb5-server-debuginfo-0:1.21.3-10.el10_2.s390x.rpm

Rocky Linux 10 ppc64le - AppStream

krb5-devel-0:1.21.3-10.el10_2.ppc64le.rpm

Rocky Linux 10 riscv64 - BaseOS

krb5-0:1.21.3-10.el10_2.src.rpm

Rocky Linux 10 aarch64 - AppStream

krb5-devel-0:1.21.3-10.el10_2.aarch64.rpm