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HIGH severity

CVE-2026-86136 — Fireware

HIGH

CVE-2026-86136 is a high-severity (CVSS 8.1) Path Traversal vulnerability in watchguard fireware. A fix is available — see the affected versions and patch details below.

A missing authorization vulnerability in the wgagent management daemon's session initialization function allows an authenticated, low-privileged user (including a read-only or guest…

Published
Updated
Affected
1 product
Patched
See advisory
Exploits
None indexed
Exploitation data as of Oct 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-86136.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs17th percentile — riskier than 17% of all scored CVEsHighest risk
0.00%0.26%0.51%0.77%0.3%0.3%Oct 26Oct 26

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2026-86136 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 383,485 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

A missing authorization vulnerability in the wgagent management daemon's session initialization function allows an authenticated, low-privileged user (including a read-only or guest administrator account) to crash the wgagent process and read arbitrary files accessible to the daemon by submitting a specially crafted management API request.

Affected Products

1 product · 4 configurations
OS
firewarewatchguard
≥ 2026.3 && < 2026.3.2
range

Detection & mitigation playbook

Vendor / appliance

  1. Detect

    Inventory every watchguard fireware deployment and check each version against the affected-products list above.

  2. Fix

    Apply the watchguard fireware security patch or hotfix for CVE-2026-86136 on the affected version, following the vendor advisory for your exact build.

  3. Workarounds

    Resolve every user-supplied path to its canonical form and reject anything that escapes the intended directory, and run the component under an account that has no read or write access outside the directory it legitimately serves. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

A missing authorization vulnerability in the wgagent management daemon's session initialization function allows an authenticated, low-privileged user (including a read-only or guest administrator account) to crash the wgagent process and read arbitrary files accessible to the daemon by submitting a specially crafted management API request.
O3 Security · Runtime Protection

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