RHSA-2026:11698 - Security Advisory

Topic

An update for ovn23.09 is now available for Fast Datapath for Red Hat Enterprise Linux 9.

Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section.

Description

OVN, the Open Virtual Network, is a system to support virtual network abstraction. OVN complements the existing capabilities of OVS to add native support for virtual network abstractions, such as virtual L2 and L3 overlays and security groups.

Security Fix(es):

• ovn: ovn: Heap Over-Read in ICMP Error Response Generation - security issue (CVE-2026-5265)
• ovn: OVN: Information disclosure via crafted DHCPv6 packets (CVE-2026-5367)

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.

Solution

For details on how to apply this update, which includes the changes described in this advisory, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux Fast Datapath 9 x86_64
• Red Hat Enterprise Linux Fast Datapath (for RHEL Server for IBM Power LE) 9 ppc64le
• Red Hat Enterprise Linux Fast Datapath (for IBM z Systems) 9 s390x
• Red Hat Enterprise Linux Fast Datapath (for RHEL for ARM 64) 9 aarch64

Fixes

• BZ - 2453458 - CVE-2026-5265 ovn: ovn: Heap Over-Read in ICMP Error Response Generation - security issue
• BZ - 2455863 - CVE-2026-5367 ovn: OVN: Information disclosure via crafted DHCPv6 packets
• FDP-3739 - OVN 23.09 FDP-OVN-26.n4 RHEL 9 Release

CVEs

• CVE-2026-5265
• CVE-2026-5367

References

• https://access.redhat.com/security/updates/classification/#important