CVE-2025-6391

Session hijacking via logged unencrypted JWTs

Published Jul 17, 2025 · Updated Jul 18, 2025

Sensitive-data exposure in Broadcom Brocade Active Support Connectivity Gateway before 3.3.0 allows local users with log access to obtain JWTs. ASCG writes JSON Web Tokens to its log files without encryption, leaving reusable session credentials readable in stored diagnostics. Exploitation requires high-privilege local access to those logs and enables unauthorized access, session hijacking, and information disclosure.

CVSS severity7.1
High
EPSS probability0.24%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Sensitive-data exposure in Broadcom Brocade Active Support Connectivity Gateway before 3.3.0 allows local users with log access to obtain JWTs. ASCG writes JSON Web Tokens to its log files without encryption, leaving reusable session credentials readable in stored diagnostics. Exploitation requires high-privilege local access to those logs and enables unauthorized access, session hijacking, and information disclosure.

The record

CVE
CVE-2025-6391
Published
Jul 17, 2025
Updated
Jul 18, 2025
Vendor
Broadcom
Product
Brocade Active Support Connectivity Gateway
Classifications
CWE-532, T1552.001
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Jul 17, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 18, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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  1. Affected versionversion=before 3.3.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

Broadcom · Brocade Active Support Connectivity Gatewayversion=before 3.3.0

Published CVSS scores

7.1Brocade Communications Systems, LLCCVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
9.1NIST National Vulnerability DatabaseCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-532Insertion of Sensitive Information into Log File
T1552.001Unsecured Credentials: Credentials In Files

Public exploit references

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Technologies

Your stack

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Your stack

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