8.9

CVE-2026-16496: hashicorp tooling Session Fixation

CVSS: 8.9v3.1HighDeferred
Published 28-07-2026Last modified 28-07-2026
Open JSON

Vulnerability summary

CVE-2026-16496 is a high (CVSS 8.9) Session Fixation vulnerability in hashicorp tooling. EPSS estimates a 0.36% chance of exploitation in the next 30 days, higher than 27.7% of scored vulnerabilities.

Overall risk
36/100
0100
Medium · default modelHow is this calculated?
CVSS score
8.9/10
010
High · v3.1 (CVE.org)
EPSS score
0.36%
0%100%
Low · -0.01 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 28-07-2026
    PublishedVulnerability first disclosed.
  2. 28-07-2026
    Last modifiedVulnerability information updated.

Description

The terraform-mcp-server before version 1.1.0 is vulnerable to an authorization bypass in the streamable-HTTP stateful transport mode that may allow a user who obtains another user's MCP session ID to have their tool calls executed using that user's Terraform credentials. This vulnerability, CVE-2026-16496, is fixed in terraform-mcp-server 1.1.0.

CVSS metrics

2 scores · 2 sources · 1 version

EPSS trend

Probability

0.36%

Chance of exploitation in the next 30 days

Percentile

28%

Versus all other CVEs

30-day change

-0.01 pp

From 0.37% on 19-09-2026

19-09-202619-10-2026
EPSS score
0.36%

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

Hashicorp1 product

1 vendor · 1 product

References

1 links