CVE-2026-5265 — When generating an ICMP Destination Unreachable or Packet
CVE-2026-5265 — 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
What This Means For You
- If your environment is affected by CWE-130, review your exposure and prioritize patching based on your environment. Monitor vendor advisories for CVE-2026-5265 updates and patches.
Related ATT&CK Techniques
🛡️ Detection Rules
3 rules · 6 SIEM formats3 detection rules auto-generated for this incident, mapped to MITRE ATT&CK. Sigma YAML is free — export to any SIEM format via the Intel Bot.
CVE-2026-5265 - Malformed ICMP Packet Triggering Heap Read
title: CVE-2026-5265 - Malformed ICMP Packet Triggering Heap Read
id: scw-2026-04-24-ai-1
status: experimental
level: critical
description: |
Detects a VM sending a malformed packet to an OVN controller that triggers an ICMP error response. This specific pattern indicates an attempt to exploit CVE-2026-5265 by sending a packet with an inflated IP length field to cause a heap read vulnerability in the ovn-controller when generating ICMP error messages.
author: SCW Feed Engine (AI-generated)
date: 2026-04-24
references:
- https://shimiscyberworld.com/posts/nvd-CVE-2026-5265/
tags:
- attack.initial_access
- attack.t1190
logsource:
category: firewall
detection:
selection:
src_ip|exact:
- 'VM_IP_ADDRESS'
dst_ip|exact:
- 'OVN_CONTROLLER_IP'
action|exact:
- 'reject'
condition: selection
falsepositives:
- Legitimate administrative activity
Source: Shimi's Cyber World · License & reuse
Indicators of Compromise
| ID | Type | Indicator |
|---|---|---|
| CVE-2026-5265 | vulnerability | CVE-2026-5265 |
| CWE-130 | weakness | CWE-130 |
Written by SCW Vulnerability Desk
Source & Attribution
| Source Platform | NVD |
| Channel | National Vulnerability Database |
| Published | April 24, 2026 at 16:16 UTC |
This content was curated and summarized by Shimi's Cyber World for informational purposes. It is not copied or republished in full. All intellectual property rights remain with the original author and source.
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