GCD AI RADAR
incidents/AIR-2026-0909

CVE-2026-87015: Open WebUI Session Cookie Leak to Tool Servers

Attack on AI2 Disclosed vulnerabilityInfrastructure vulnerabilityData leak

Open WebUI improperly handles session cookies when multiple external tool servers are called in a single request, leaking authentication cookies to unintended endpoints. The issue arises from late cookie jar evaluation across connections.

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 leak
    Training data, chat logs, system prompts, model weights or other AI-system data exposed.
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
10 Sep 2026
first reported
9 Sep 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-2026-87015 · open-webui · cookie-leak
record
created 2026-10-18 07:00Z · updated 2026-10-18 10:04Z · json

Sources · 2

  1. 2026-09-09
    CVE-2026-87015: Open WebUI is an extensible, feature-rich, and user-friendly self-hosted AI platform.
    NVD · nvd.nist.gov/vuln/detail/CVE-2026-87015
  2. 2026-09-10
    CVE-2026-87015: Open WebUI: A user's session cookies are sent to tool servers configured for bearer authentication
    GitHub Advisory Database · github.com/advisories/GHSA-p78m-89r6-pgf7

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