CriticalCVE-2026-112710

    WatchGuard Fireware OS: Heap-based Buffer Overflow (CVE-2026-112710)

    Published Last modified Sources: CVE.org, pwn.watch

    What is affected, what to do

    A heap-based buffer overflow vulnerability exists in the Fireware OS authentication service allows an attacker who controls or intercepts traffic to the configured Active Directory server to create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.

    Update WatchGuard Fireware OS to version 2026.4, WatchGuard Fireware OS to version 12.12.4, WatchGuard Fireware OS to version 12.5.22.

    Affected
    • WatchGuard Fireware OS lt 2025.1..2026.4
    • WatchGuard Fireware OS lt 12.0..12.12.4
    • WatchGuard Fireware OS lt 12.0..12.5.22
    Fixed in
    • WatchGuard Fireware OS 2026.4
    • WatchGuard Fireware OS 12.12.4
    • WatchGuard Fireware OS 12.5.22

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    9.2

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v4

    9.2

    CVSS v4

    Severity Critical on the scale from 0 to 10.

    Source: CVE.org, pwn.watch

    —

    EPSS score

    No value is available for this vulnerability.

    Show all metrics
    Severity
    Critical
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    76.00 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    9.2 Methodology
    CVSS v4

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    9.2
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-122, CWE-131

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    High technical severity: assess and remediate the vulnerability in vulnerability handling under Art. 21(2)(e) NIS2 and document the decision.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    A heap-based buffer overflow vulnerability exists in the Fireware OS authentication service allows an attacker who controls or intercepts traffic to the configured Active Directory server to create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.

    Source: cvelistv5, pwn.watch, NVD (NIST)

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    WatchGuardFireware OS
    • 12.0 – < 12.12.4
    • 12.0 – < 12.5.22
    • 2025.1 – < 2026.4
    • 12.12.4
    • 12.5.22
    • 2026.4

    Vendors and products

    Weakness classes (CWE)

    • CWE-122Heap-based Buffer Overflow

      Variant

      A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().

      Entry at MITRE CWE-122

    • CWE-131Incorrect Calculation of Buffer Size

      Base

      The product does not correctly calculate the size to be used when allocating a buffer, which could lead to a buffer overflow.

      Entry at MITRE CWE-131

    References & sources

    • psirt.watchguard.comCVE-2026-112710Vendor advisory
    • pwn.watchpwn.watch: WatchGuard Fireware OS 2026.4 and 12.12.4 fix 17 Firebox flaws, including unauthenticated bugs in the SIP proxy, Access Portal and FireClusterpwn-watch
    • psirt.watchguard.comWatchGuard Security Advisories (Oct 27 2026 batch)pwn-watch
    • psirt.watchguard.comCVE-2026-93857: Fireware OS Pre-Authentication Stack Buffer Overflow in SIP Proxy Allows Remote Code Executionpwn-watch
    • psirt.watchguard.comCVE-2026-93866: Fireware OS Pre-Authentication Integer Overflow in Access Portal Allows Out-of-Bounds Writepwn-watch
    • psirt.watchguard.comCVE-2026-93865: Fireware OS Missing Authentication in FireCluster Sync Daemon Allows Remote Root Action Injectionpwn-watch
    • psirt.watchguard.comCVE-2026-112710: Fireware OS Heap Buffer Overflow in AD Authentication Service Allows Pre-Authentication Remote Code Executionpwn-watch
    • psirt.watchguard.comCVE-2026-103594: Fireware OS Stack Buffer Overflow in WireGuard Configuration Allows Remote Code Executionpwn-watch
    • psirt.watchguard.comCVE-2026-103593: Fireware OS Stack Buffer Overflow in Logging Service Allows Remote Code Executionpwn-watch

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. ReceivedWatchGuard

      CVSS V4.0: AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

      Weakness type: CWE-122, CWE-131

      Description added or changed

      Show 6 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      A heap-based buffer overflow vulnerability exists in the Fireware OS authentication service allows an attacker who controls or intercepts traffic to the configured Active Directory server to create a denial of service condition and potentially execute arbitrary code by returning a specially crafted response.
      CVSSadded
      —
      AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
      Weakness type (CWE)added
      —
      CWE-122
      Weakness type (CWE)added
      —
      CWE-131
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/112xxx/CVE-2026-112710.json">CVE-2026-112710</a>
      Referenceadded
      —
      https://psirt.watchguard.com/CVE-2026-112710

      Source identifier: 5d1c2695-1a31-4499-88ae-e847036fd7e3

    Embed badge

    Show the severity and KEV status of this vulnerability on your site – with a link back here. The image is updated hourly.

    Badge preview for CVE-2026-112710
    <a href="https://intel.neosec.eu/en/cve/CVE-2026-112710"><img src="https://intel.neosec.eu/badge/cve/CVE-2026-112710.svg?lang=en" alt="CVE-2026-112710 – NEOSEC Intel" height="20"></a>