GCD AI RADAR
incidents/AIR-2026-0526

CVE-2026-28788: Open WebUI File Overwrite Vulnerability

Attack on AI2 Disclosed vulnerabilityInfrastructure vulnerabilityData poisoning

A missing ownership check in Open WebUI's file batch processing endpoint allowed authenticated users to overwrite arbitrary files in shared knowledge bases. The manipulated files could subsequently poison RAG responses provided to LLM users.

disclosed CVENo confirmed exploitation, so this record is tracked as a disclosed vulnerability and not counted as an incident. It moves into the counts if CISA or the vendor confirms exploitation. Why

Details

type
Attack on AI
An AI model, agent or AI-powered product was the thing exploited, abused or leaked.
categories
  • Infrastructure vulnerabilityprimary
    CVEs and advisories in AI frameworks, inference servers, MCP servers, AI developer tools and hosting stacks.
  • Data poisoning
    Training or retrieval data manipulated to change model behaviour.
owasp llm top 10
mitre atlas
no technique for these categories
Both rows are derived from the type and categories (OWASP 2025 edition, ATLAS release 2026.09), not classified per record. How
severity
2 · Disclosed vulnerability
CVE or vendor advisory, patched or patchable, no confirmed exploitation.
targets
Framework / tooling
products
Open WebUI
incident date
27 Mar 2026
first reported
27 Mar 2026
origin
GitHub Advisory Database
Vulnerability record from NVD / the GitHub Advisory Database. This product uses the NVD API but is not endorsed or certified by the NVD.
classifier confidence
0.95 · published at or above 0.80; see the methodology
tags
CVE-2026-28788 · open-webui · rag
record
created 2026-10-18 07:00Z · updated 2026-10-18 10:04Z · json

Sources · 2

  1. 2026-03-27
    CVE-2026-28788: Open WebUI's process_files_batch() endpoint missing ownership check, allows unauthorized file overwrite
    GitHub Advisory Database · github.com/advisories/GHSA-jjp7-g2jw-wh3j
  2. 2026-03-27
    CVE-2026-28788: Open WebUI is a self-hosted artificial intelligence platform designed to operate entirely offline.
    NVD · nvd.nist.gov/vuln/detail/CVE-2026-28788

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