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TI-2026-71765 Aliases CVE-2026-53711

Stored cross-site scripting in MCP ContextForge Global Prompts

Priority MEDIUM 56CWE-79Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
Passive
Attack complexity
Low
Attack requirements
None
Impact type
Cross-site scripting
Confidentiality · integrity · availability
None · None · None
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-79.

Summary

IBM mcp-context-forge from 0.2.0 before 0.3.1 contains a stored cross-site scripting flaw in its Global Prompts feature. The MCP Admin UI renders saved prompt templates without sufficient output encoding (CWE-79). An authenticated attacker can save markup with script-capable event handlers that runs when another user views the saved prompt. The script can alter the interface, present phishing content, observe keystrokes and act with the viewer's browser session.

Written with Claude Haiku 5.5 from the sources below · 2026-10-27

Description from the CNA

MCP Context Forge provides an MCP Admin UI for managing gateway resources. From 0.2.0 until 0.3.1, the Global Prompts feature stores a prompt template without sufficient output encoding before the MCP Admin UI renders it. An authenticated attacker can save markup containing script-capable event handlers, and the code executes when another user views the saved prompt. The stored cross-site scripting can alter the interface, present phishing content, observe keystrokes available to the page, and act with the viewer's browser session. This issue is fixed in version 0.3.1.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00363 30th percentileScored 2026-11-07
Fix Fixed mcp-context-forge (IBM): 0.3.1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
IBMmcp-context-forge0.2.0 to before 0.3.10.3.1Patch availableCNA
  • mcp-context-forge VendorIBM Affected 0.2.0 to before 0.3.1 Fixed in 0.3.1 Patch available CNA

Remediation

Upgrade mcp-context-forge to version 0.3.1, which fixes the issue.

Written with Claude Haiku 5.5 from the sources below · 2026-10-27

  • Fix · CNA mcp-context-forge (IBM) Fixed in 0.3.1

Timeline

  1. 2026-10-13 Threatist record created from CVE-2026-53711

References

Other 4

  • TI-2026-08085 Unauthenticated Remote Code Execution via Auto-Login Bypass and Code Validation KEVCVSS 3.1CRITICAL 9.8
  • TI-2022-23774 IBM Aspera Faspex code execution KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-03794 Improper authentication in IBM Data Risk Manager KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-03441 Code injection in IBM Planning Analytics KEVCVSS 3.1CRITICAL 9.8
  • TI-2017-03639 Improper handling of exceptional conditions in Apache Struts KEVCVSS 3.1CRITICAL 9.8
  • TI-2015-06198 Serialized-object interfaces in certain IBM analytics, business solutions, cognitive, IT… KEVCVSS 3.1CRITICAL 9.8
See all 9711 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences