RHSA-2026:57483HighCVSS 9.0

Red Hat Security Advisory: OpenShift Container Platform 4.18.54 bug fix and security update

Published
August 26, 2026
Last Modified
August 26, 2026

🔗 CVE IDs covered (20)

CVE-2026-35177 →CVE-2026-41411 →CVE-2026-42011 →CVE-2026-1933 →CVE-2026-4408 →CVE-2026-5260 →CVE-2026-14476 →CVE-2026-34982 →CVE-2026-42010 →CVE-2026-48864 →CVE-2026-42009 →CVE-2026-42013 →CVE-2026-46483 →CVE-2026-64531 →CVE-2026-2340 →CVE-2026-3012 →CVE-2026-5450 →CVE-2026-14474 →CVE-2026-33845 →CVE-2026-33846 →

📋 Description

CVE-2026-1933 — samba: Missing access check on reparse point operations CVE-2026-2340 — samba: vfs_worm does not block directory modification CVE-2026-3012 — samba: group policy certificate enrollment uses http:// without validation CVE-2026-4408 — samba: Remote Code Execution in SAMR CVE-2026-5260 — gnutls: gnutls: Information disclosure via heap overread in RSA key exchange CVE-2026-5450 — glibc: glibc: Heap Buffer Overflow in scanf with %mc format specifier and large width CVE-2026-14474 — sssd: sssd: sudo LDAP provider searches entire directory tree for sudoRole objects by default, enabling privilege escalation CVE-2026-14476 — sssd: sssd: GPO cache path traversal via unsanitized gPCFileSysPath allows Kerberos authentication bypass CVE-2026-33845 — gnutls: GnuTLS: Denial of Service via DTLS zero-length fragment CVE-2026-33846 — gnutls: GnuTLS: Denial of Service via heap buffer overflow in DTLS handshake fragment reassembly CVE-2026-34982 — vim: arbitrary command execution via modeline sandbox bypass CVE-2026-35177 — vim: zip.vim: Vim zip.vim plugin: Arbitrary file overwrite via path traversal bypass CVE-2026-41411 — vim: Vim: Command injection allows arbitrary code execution via malicious tag files CVE-2026-42009 — gnutls: gnutls: Denial of Service via DTLS packet reordering vulnerability CVE-2026-42010 — gnutls: gnutls: Authentication Bypass via NUL Character in Username CVE-2026-42011 — gnutls: gnutls: Security bypass due to incorrect name constraint handling CVE-2026-42013 — gnutls: gnutls: Certificate validation bypass due to oversized Subject Alternative Name CVE-2026-46483 — vim: command injection when decompressing .tgz archives CVE-2026-48864 — libsolv: Heap buffer overflow in libsolv repopagestore via unchecked decompression of malicious .solv page data CVE-2026-64531 — kernel: net: openvswitch: reject oversized nested action attrs

🎯 Affected products5

  • Red Hat OpenShift Container Platform 4.18
  • rhcos-aarch64-418.94.202608142238-0 as a component of Red Hat OpenShift Container Platform 4.18
  • rhcos-ppc64le-418.94.202608142238-0 as a component of Red Hat OpenShift Container Platform 4.18
  • rhcos-s390x-418.94.202608142238-0 as a component of Red Hat OpenShift Container Platform 4.18
  • rhcos-x86_64-418.94.202608142238-0 as a component of Red Hat OpenShift Container Platform 4.18

✅ Remediation

For OpenShift Container Platform 4.18 see the following documentation, which will be updated shortly for this release, for important instructions on how to upgrade your cluster and fully apply this asynchronous errata update: https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html/release_notes/ You may download the oc tool and use it to inspect release image metadata for x86_64, s390x, ppc64le, and aarch64 architectures. The image digests may be found at https://quay.io/repository/openshift-release-dev/ocp-release?tab=tags. The sha values for the release are as follows: (For x86_64 architecture) The image digest is sha256:4d4e6147f15c286b33afbd6838ed94683b5f93711a90efe046c58d453318663c (For s390x architecture) The image digest is sha256:66a3f21ee82c3651eae07ef0cd7dc81859a06b9c48b0e727489a6945a1fca830 (For ppc64le architecture) The image digest is sha256:e6f5a4487f2a5a040ed850a80b6014af330ac162beaada80b2b21a9bd79353ed (For aarch64 architecture) The image digest is sha256:bac5e091e587bba94d10d0e64d6c664748f2106f020d219b08247065850b4f80 All OpenShift Container Platform 4.18 users are advised to upgrade to these updated packages and images when they are available in the appropriate release channel. To check for available updates, use the OpenShift CLI (oc) or web console. Instructions for upgrading a cluster are available at https://docs.redhat.com/en/documentation/openshift_container_platform/4.18/html-single/updating_clusters/index#updating-cluster-cli. Workaround: Administrators can mitigate this issue by ensuring users who access a read only = yes Samba share do not have filesystem-level write permission to the exported files. A server administrator may also monitor and remove unintended "user.SmbReparse" xattr (extended attributes) and the associated FILE_ATTRIBUTE_REPARSE_POINT "user.DosAttrib" bit metadata if exploitation is suspected. Workaround: Administrators can mitigate this issue by: Setting read-only permissions on protected files at the underlying filesystem level will prevent modifications. Configuring ```worm:grace_period = 0``` (zero or less) in smb.conf will eliminate the writable grace period (will eliminate the window in which the rename can happen), understanding that this may impact workflows requiring multi-step file creation. Workaround: Systems are not affected unless Samba Group Policy processing and certificate auto-enrollment are explicitly enabled. Administrators can reduce exposure by: Avoiding unnecessary use of certificate auto-enrollment. Ensuring your "smb.conf" does not contain a line like ```apply group policies = yes```. If , group policy is not be enabled, the vulnerable code will not run. Intercepting the HTTP request requires some control over the local network or other devices to intercept or redirect traffic. Some network administrators might assess this as a low risk on their networks. Workaround: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability. Workaround: Set ldap_sudo_search_base explicitly in /etc/sssd/sssd.conf to restrict the search to the designated sudoers container: [domain/example.com] ldap_sudo_search_base = ou=sudoers,dc=example,dc=com Additionally, restrict LDAP ACLs to prevent non-admin principals from creating sudoRole objects outside the designated sudoers container. Workaround: Set ad_gpo_access_control = disabled in /etc/sssd/sssd.conf to disable GPO fetching entirely. Note that this removes GPO-based login policy enforcement. Workaround: To mitigate this issue, disable the modeline support by adding the following command to the Vim configuration file: ~~~ set nomodeline ~~~ Workaround: Avoid opening untrusted zip archives with Vim. This operational control prevents the necessary user interaction required to trigger the path traversal vulnerability in the `zip.vim` plugin. Workaround: Mitigation for this issue involves exercising caution when opening or processing tag files from untrusted sources. Users should avoid loading tag files from unknown or suspicious origins to prevent the execution of arbitrary commands. Workaround: To mitigate this vulnerability, do not decompress untrusted .tgz archives with the Vimuntar command. Use 'tar -x -z -f' directly, instead. Workaround: Disclaimer: The following mitigation solutions are provided as a courtesy, pending the application of an official patch. This content was generated utilizing AI tools in conjunction with data from cmetaxonomy.org. Customers are advised to independently evaluate and test these temporary mitigations within their own infrastructure. If OVS is not required on a given system, unloading the openvswitch module (`modprobe -r openvswitch`) eliminates the attack surface entirely. For systems that require OVS but cannot patch immediately, the single most effective mitigation is disabling unprivileged user namespaces (`sysctluser.max_user_namespaces=0`), which blocks the primary path an unprivileged attacker uses to obtain CAP_NET_ADMIN and reach the vulnerable netlink interface. Standard kernel hardening (KASLR, SMEP, SMAP, kptr_restrict) is enabled by default on supported RHEL kernels and significantly increases exploitation complexity, but these controls are defense-in-depth and not a substitute for patching or removing the vulnerable module.

🔗 References (23)