CVE-2026-86104

validatedZero produced an exploit or a check.

GHSA-44q2-m4gj-p5w4 ↗EUVD-2026-89501 ↗

check availableZero validated a working check for it.not proven exploitableZero has a detection check, but hasn't produced a full working exploit yet.
cve.orgpublic pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).kevAttacks confirmed in the real world.
WatchGuard Fireware OS >= 2026.3, < 2026.3.2; >= 2025.0, < 2026.2.3; >= 12.0, < 12.12.3; >= 12.0, < 12.5.21
fixed in 2026.3.2, 2026.2.3, 12.12.3, 12.5.21
CWE-400 Uncontrolled Resource Consumption
ETK-2026-43, permanent identifier
+17dTTV
1h 46mAI analysisAnalysis: how long the AI spent reversing this signal.
Check if you are vulnerable
timeline
0 = trigger signal
trigger signal (cve.org) +0dcheck available+17dagent stopped
0
+5d
+10d
+15d

description

WatchGuard Fireware OS contains an uncontrolled resource-consumption issue in its wgagent login process. A remote attacker without authentication can cause denial of service by sending a crafted request to the affected service.

mitigation

Upgrade Fireware OS to 2026.3.2, 2026.2.3, 12.12.3, or 12.5.21, as applicable to the appliance and release train.

fixed in 2026.3.2, 2026.2.3, 12.12.3, 12.5.21

check
available
exploit
no
automationDeterministic: a check that runs on its own, the same request on every target. Contextual: an agentic technique that needs to be applied per target, for bugs that depend on contextual flows.
deterministic
auth requiredWhether an attacker needs an account first, based on the CVSS vector's Privileges Required.
no
EPSSEstimate of the chance this CVE is exploited in the next 30 days. Refreshed daily.
0.36%28th percentile
agent run time
1h 46m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-09-29 23:05Z
Δ to public pocExploit code has been published by someone. Source signals can also carry a PoC (Proof of Concept).
–
Δ to kevAttacks confirmed in the real world.
–

outcome

Check only, differential: the check fires on the vulnerable build and is silent on the patched one.

source signals

Public signals that triggered or updated the pipeline. These are inputs for the deltas above.

  1. 2026-09-29 23:05Z
    cve_org: trigger signal, started the run

this entry in the feed

GET /api/v1/feed/CVE-2026-86104

{
  "etk_id": "ETK-2026-43",
  "cve_id": "CVE-2026-86104",
  "display_id": "CVE-2026-86104",
  "ghsa_id": "GHSA-44q2-m4gj-p5w4",
  "euvd_id": "EUVD-2026-89501",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Unauthenticated resource exhaustion in Fireware OS login process",
  "summary": "WatchGuard Fireware OS contains an uncontrolled resource-consumption issue in its wgagent login process. A remote attacker without authentication can cause denial of service by sending a crafted request to the affected service.",
  "mitigation": "Upgrade Fireware OS to 2026.3.2, 2026.2.3, 12.12.3, or 12.5.21, as applicable to the appliance and release train.",
  "vendor": "WatchGuard",
  "product": "Fireware OS",
  "affected": [
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 2026.3, < 2026.3.2",
        ">= 2025.0, < 2026.2.3",
        ">= 12.0, < 12.12.3"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "2026.3.2",
        "2026.2.3",
        "12.12.3"
      ],
      "package_name": "Fireware OS",
      "purl": null
    },
    {
      "affected_notes": [],
      "affected_ranges": [
        ">= 12.0, < 12.5.21"
      ],
      "ecosystem": null,
      "fixed_versions": [
        "12.5.21"
      ],
      "package_name": "Fireware OS",
      "purl": null
    }
  ],
  "cwes": [
    400
  ],
  "cvss_score": 8.7,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N",
  "epss_score": 0.0036,
  "epss_percentile": 0.2856,
  "epss_asof": "2026-10-20",
  "automation": "deterministic",
  "check": true,
  "check_confidence_basis": "differential",
  "exploit": false,
  "pipeline_minutes": 106.40332095,
  "t0_at": "2026-09-29T23:05:48.197000+00:00",
  "signals": {
    "check": {
      "at": "2026-10-17T02:55:27.821479+00:00",
      "days": 17.15948639443287,
      "is_lower_bound": false,
      "measured_at": "2026-09-29T23:05:48.197000+00:00",
      "url": null
    },
    "trigger_signal": {
      "at": "2026-09-29T23:05:48.197000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-09-29T23:05:48.197000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-86104"
    }
  }
}

published 2026-09-29 23:42Z
last change 2026-10-21 04:45Z

Need the technical details behind an entry?

Every entry here shows what we attempted and when. The technical details, the generated exploit that fired it and the evidence behind the verdict are not public. Tell us about your use case and we’ll get back to you about extended API access.