CVE-2026-7535 — Open5GS Denial of Service

title: CVE-2026-7535 - Open5GS AMF Registration Status Update DoS
id: scw-2026-05-01-ai-1
status: experimental
level: high
description: |
  Detects the specific HTTP PUT request pattern targeting the AMF transfer-update endpoint with a query parameter indicative of the registration status update, which is exploited in CVE-2026-7535 to cause a denial of service by manipulating the ueContextId.
author: SCW Feed Engine (AI-generated)
date: 2026-05-01
references:
  - https://shimiscyberworld.com/posts/nvd-CVE-2026-7535/
tags:
  - attack.initial_access
  - attack.t1190
logsource:
    category: webserver
detection:
  selection:
      cs-method:
          - 'PUT'
      cs-uri:
          - '/namf-comm/v1/ue-contexts/*/transfer-update'
      cs-uri-query|contains:
          - 'registrationStatusUpdate'
  condition: selection
falsepositives:
  - Legitimate administrative activity

Source: Shimi's Cyber World · License & reuse