CVE-2026-78174: WatchGuard Dimension Session Hijack via Exposed Session Tokens in Diagnostic Logs

Severity: critical (CVSS 9.3 v4.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-28 · updated 2026-08-28
Weakness: CWE-200

Description

WatchGuard Dimension records unredacted session identifiers for logged-in users in its web UI diagnostic log. A low-privileged Dimension Administrator can retrieve this log and extract a Super Administrator's session token while that administrator is logged in, enabling account takeover.

Affected products

WatchGuard Dimension: from 2.0 before 2.3.1 — fixed in 2.3.1

How to fix

Upgrade to a fixed version: WatchGuard Dimension 2.3.1. Check the vendor advisory for mitigations.

References

https://psirt.watchguard.com/CVE-2026-78174

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