5.4

CVE-2026-11918: ibm contextforge mcp gateway Incomplete List of Disallowed Inputs

CVSS: 5.4v3.1MediumAwaiting analysis
Published 15-09-2026Last modified 20-09-2026
Open JSON

Vulnerability summary

CVE-2026-11918 is a medium (CVSS 5.4) Incomplete List of Disallowed Inputs vulnerability in ibm contextforge mcp gateway. EPSS estimates a 0.16% chance of exploitation in the next 30 days, higher than 5.1% of scored vulnerabilities.

Overall risk
22/100
0100
Low · default modelHow is this calculated?
CVSS score
5.4/10
010
Medium · v3.1 (CVE.org)
EPSS score
0.16%
0%100%
Low · -0.11 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 15-09-2026
    PublishedVulnerability first disclosed.
  2. 20-09-2026
    Last modifiedVulnerability information updated.

Description

IBM ContextForge MCP Gateway <= v1.0.4 IBM mcp-context-forge could allow an authenticated user to bypass protection mechanisms due to incomplete recursive inspection of nested payload content.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.16%

Chance of exploitation in the next 30 days

Percentile

5%

Versus all other CVEs

30-day change

-0.11 pp

From 0.27% on 20-09-2026

20-09-202620-10-2026
EPSS score
0.16%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Ibm1 product

1 vendor · 1 product

References

1 links