CVE-2026-7707 — Open5GS Denial of Service

title: CVE-2026-7707 - Open5GS UDR Subscription Context Denial of Service
id: scw-2026-05-03-ai-1
status: experimental
level: critical
description: |
  Detects attempts to exploit CVE-2026-7707 by targeting the Open5GS UDR subscription context handler. The vulnerability lies in the manipulation of the 'pei' argument in requests to the '/udr/v1/subscription_context' endpoint, leading to a denial of service. This rule specifically looks for POST requests to this URI containing the 'pei=' parameter, indicating a potential exploit attempt.
author: SCW Feed Engine (AI-generated)
date: 2026-05-03
references:
  - https://shimiscyberworld.com/posts/nvd-CVE-2026-7707/
tags:
  - attack.initial_access
  - attack.t1190
logsource:
    category: webserver
detection:
  selection:
      cs-uri|contains:
          - '/udr/v1/subscription_context'
      cs-method:
          - 'POST'
      cs-uri-query|contains:
          - 'pei='
  condition: selection
falsepositives:
  - Legitimate administrative activity

Source: Shimi's Cyber World · License & reuse