CVE-2026-13086

Root code execution via epm buffer overflow

Published Aug 27, 2026 · Updated Aug 27, 2026

A stack-based buffer overflow in Fireware OS epm allows remote attackers on a trusted interface to execute arbitrary code as root. Epm JSON-RPC processing copies attacker-controlled data into a fixed-length stack buffer without first validating its length, allowing the saved return address to be overwritten. Authentication is not required, but access is limited to a trusted interface; failed attempts can crash epm until the service respawns.

CVSS severity9.3
Critical
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

A stack-based buffer overflow in Fireware OS epm allows remote attackers on a trusted interface to execute arbitrary code as root. Epm JSON-RPC processing copies attacker-controlled data into a fixed-length stack buffer without first validating its length, allowing the saved return address to be overwritten. Authentication is not required, but access is limited to a trusted interface; failed attempts can crash epm until the service respawns.

The record

CVE
CVE-2026-13086
Published
Aug 27, 2026
Updated
Aug 27, 2026
Vendor
WatchGuard Technologies, Inc.
Product
Fireware OS
Classifications
CWE-787, CWE-798, CWE-121, CAPEC-46, CAPEC-100, T1210
Attack vector
adjacent
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=12.0 <12.12.2
  2. Affected versionversion=12.0 <12.5.20
  3. Affected versionversion=2025.0 <2026.2.2

What conditions does exploitation require?

Attack vectoradjacent
Required privilegesunauthenticated

What is affected?

WatchGuard Technologies, Inc. · Fireware OSversion=12.0 <12.12.2; version=12.0 <12.5.20; version=2025.0 <2026.2.2

Published CVSS scores

9.3WatchGuard PSIRTCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
8.8TrendAI Zero Day InitiativeCVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectoradjacent
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
CWE-798Use of Hard-coded Credentials
CWE-121Stack-based Buffer Overflow
CAPEC-46Overflow Variables and Tags
CAPEC-100Overflow Buffers
T1210Exploitation of Remote Services

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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