CVE-2026-40968 — When an authenticated user is denied access to a gRPC

title: Spring gRPC Authenticated Identity Leakage - CVE-2026-40968
id: scw-2026-04-28-ai-1
status: experimental
level: high
description: |
  Detects an authenticated user being denied access to a gRPC endpoint, which is a precursor to the vulnerability in CVE-2026-40968 where the authenticated identity might persist and be inherited by subsequent unauthenticated requests, leading to privilege escalation.
author: SCW Feed Engine (AI-generated)
date: 2026-04-28
references:
  - https://shimiscyberworld.com/posts/nvd-CVE-2026-40968/
tags:
  - attack.initial_access
  - attack.t1190
logsource:
    category: webserver
detection:
  selection:
      cs-uri|contains:
          - '/.well-known/grpc'
      sc-status:
          - 403
      condition: selection
falsepositives:
  - Legitimate administrative activity

Source: Shimi's Cyber World · License & reuse