CVE-2026-5265
Description
When generating an ICMP Destination Unreachable or Packet Too Big response, the handler copies a portion of the original packet into the ICMP error body using the IP header's self-declared total length (ip_tot_len for IPv4, ip6_plen for IPv6) without validating it against the actual packet buffer size. A VM can send a short packet with an inflated IP length field that triggers an ICMP error (e.g., by hitting a reject ACL), causing ovn-controller to read heap memory beyond the valid packet data and include it in the ICMP response sent back to the VM.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
Vendor advisory: debian — https://security-tracker.debian.org/tracker/CVE-2026-5265
Vendor advisory: suse — https://www.suse.com/security/cve/CVE-2026-5265.html
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| sles | affected | | |
| debian | bookworm | affected | |
| debian | forky | fixed | 26.03.0-4 |
| debian | sid | fixed | 26.03.0-4 |
| debian | trixie | affected | |
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/security/cve/CVE-2026-5265
- https://bugzilla.redhat.com/show_bug.cgi?id=2453458
- http://www.openwall.com/lists/oss-security/2026/04/20/2
- http://www.openwall.com/lists/oss-security/2026/04/20/4
- https://www.suse.com/security/cve/CVE-2026-5265.html
- https://security-tracker.debian.org/tracker/CVE-2026-5265
CWEs
CWE-130
Verify integrity in audit chain (admin only). AS-IS.