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CVE.org (no NVD analysis yet)· CNA WatchGuard

CVE-2026-90442: Fireware OS Authenticated Stack Buffer Overflow in certd Allows Denial of Service

Noroxi assessment

Priority: Monitor (action score 34/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.24% (FIRST EPSS).
  • Anyone who can reach it over the internet can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

A stack-based buffer overflow vulnerability in the Fireware OS certd process allows an authenticated attacker with access to the Firebox management interface to crash the certificate management service and potentially execute arbitrary code by sending a specially crafted request.

HighCVSS 8.6 · v4.0—No exploit No fix recorded
Published
Oct 27, 2026
Updated
Nov 4, 2026
EPSS
0.2% · 15th percentile

Report tools

JSON

Action score

34

Monitor

Low priority for now.

CVSS
34 / 40 · 8.6 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.2%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · WatchGuard
8.6
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • No fixed version yet

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2026-90442

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

One daily email digest (06:00 UTC); connect a webhook for KEV listings and weaponized exploits instantly.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

—

Versions reported by the vendor

Affected version ranges reported by the assigning authority (WatchGuard). Independent of NVD's CPE analysis and usually ahead of it.

  • WatchGuard Fireware OS

    • 2025.1 and later · before 2026.4affected
    • 12.0 and later · before 12.12.4affected
    • 12.0 and later · before 12.5.22affected

Same product

watchguard: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-103594Fireware OS Stack Buffer Overflow in WireGuard Configuration Allows Remote Code Execution
    38Monitor
  • CVE-2026-90465Fireware OS Missing Authentication in FireCluster Sync Allows Privilege Escalation
    37Monitor
  • CVE-2026-19318Fireware OS Pre-Authentication Stack Buffer Overflow in iked Allows Remote Code Execution
    37Monitor

Published before and after this one in the same product

  • ← EarlierCVE-2026-113881Oct 27, 2026 · Fireware OS Stack Buffer Overflow in VPN Network Access Enforcement Allows Unprivileged Code Execution
    24Monitor
  • ← EarlierCVE-2026-82332Oct 27, 2026 · Fireware OS Improper Authentication in AuthPoint MFA Verification Allows Session Hijacking
    22Monitor
  • Later →CVE-2026-90464Oct 27, 2026 · Fireware OS Missing Command Validation allows Authenticated Arbitrary File Modification as Root
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-1035940 days apartFireware OS Stack Buffer Overflow in WireGuard Configuration Allows Remote Code Execution
    38Monitor
  • CVE-2026-1308661 days apartFireware OS Stack-Based Buffer Overflow in Mobile Security epm Endpoint
    37Monitor
  • CVE-2026-1931861 days apartFireware OS Pre-Authentication Stack Buffer Overflow in iked Allows Remote Code Execution
    37Monitor
  • CVE-2026-7801061 days apartFireware OS Stack-Based Buffer Overflow in iked Allows Unauthenticated Denial of Service
    34Monitor
  • CVE-2026-1035930 days apartFireware OS Stack Buffer Overflow in Logging Service Allows Remote Code Execution
    28Monitor
  • CVE-2026-1138810 days apartFireware OS Stack Buffer Overflow in VPN Network Access Enforcement Allows Unprivileged Code Execution
    24Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

  • CVE-2026-904650 days apartFireware OS Missing Authentication in FireCluster Sync Allows Privilege Escalation
    37Monitor
  • CVE-2026-938650 days apartFireware OS Missing Authentication in FireCluster Sync Daemon Allows Remote Root Action Injection
    36Monitor
  • CVE-2026-1043810 days apartFireware OS Missing Authentication in FireCluster State Sync Allows BOVPN Tunnel Denial of Service
    24Monitor
  • CVE-2026-823320 days apartFireware OS Improper Authentication in AuthPoint MFA Verification Allows Session Hijacking
    22Monitor

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Network
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
X

Weakness class (CWE)

CWE-121 · Stack-based Buffer Overflow

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:L/SI:L/SA:L/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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

Change log

  1. SSVC exploitation— → none
  2. Exploit maturity— → none

For records you follow, these changes also arrive as notifications. →

References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records