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Fencer Intel
medium 6.3

CVE-2026-9831 json

ExtremeCloud IQ Cross Tenant Data Exposure via Extreme Platform One Authentication Race Condition

published 5mo ago modified 3mo ago also EUVD-2026-33445

cvss
6.3
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

A race condition in the shared Extreme Platform ONE IAM Gateway API-key authentication path could, under specific high-concurrency traffic conditions, intermittently allow requests authenticated with an Extreme Platform ONE /IAM-issued API key to receive response data for another tenant. The issue was observed through ExtremeCloud IQ/XIQ API endpoints and validated against both XIQ/XAPI and Extreme Platform ONE /Common Services API paths. XIQ-native tokens and standard OAuth/Bearer JWT authentication were not affected.

Patch / fix

  • Extreme Networks Extreme Platform ONE 25.10.0-104

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CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
5mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-11).

CVSS scores

assigned by version score vector
CNA 3.1 6.3 CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N

Affected products

  • Extreme Networks Extreme Platform ONE

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization
  • CWE-488 Exposure of Data Element to Wrong Session

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.