# CVE-2026-5265: ovn25.03: When generating an ICMP Destination Unreachable or Packet Too Big response, the handler copies a portion of the origi...

CVE-2026-5265 is fixed in 3 products on 1 platform, first by RHSA-2026:22110, released April 13, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-5265
- Priority: Routine
- CVSS: 6.5 (moderate)
- EPSS: 0.0063
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 6, 2026

## 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.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | openvswitch opensuse-leap 16.0 | 3.5.4-160000.4.1 | [OPENSUSE-SU-2026:20972-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-20972-1.md) | Jun 17, 2026 |
| Linux | openvswitch sles 15.6 | 3.1.7-150600.33.15.1 | [SUSE-SU-2026:2475-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2475-1.md) | Jun 22, 2026 |
| Linux | openvswitch sles 15.7 | 3.5.4-150700.41.18.1 | [SUSE-SU-2026:2463-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2463-1.md) | Jun 19, 2026 |
| Linux | openvswitch sles 16.0 | 3.5.4-160000.4.1 | [SUSE-SU-2026:22152-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22152-1.md) | Jun 17, 2026 |
| Linux | ovn25.03 RHEL 10 | 25.03.2-100.el10fdp | [RHSA-2026:22110](https://patchblox.com/security/data/fix/linux/rhsa-2026-22110.md) | Apr 13, 2026 |
| Linux | ovn25.09 RHEL 10 | 25.09.2-103.el10fdp | [RHSA-2026:22111](https://patchblox.com/security/data/fix/linux/rhsa-2026-22111.md) | Apr 13, 2026 |

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Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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