CVE-2026-109373

validatedZero produced an exploit or a check.

GHSA-ff7c-8692-c559 ↗EUVD-2026-97671 ↗

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.
zitadel 4.0.0 - 4.19.1; 3.0.0 - 3.4.15
fixed in 4.19.2
CWE-441 Unintended Proxy or Intermediary ('Confused Deputy')
ETK-2026-1387Zero's internal tracking ID, independent of the CVE number., permanent identifier
+1h22mTTV
21mAI analysisAnalysis: how long the AI spent reversing this signal.
Check if you are vulnerable
timeline
0 = cve.org publication
trigger signal (cve.org) +0mcheck available+82magent stopped
0
+30min
+60min
+90min

description

ZITADEL versions 3.0.0 through 4.19.1 are affected by an authentication bypass in the Login V2 UI. An unauthenticated attacker may obtain session tokens and take over user accounts, including administrator accounts, by abusing improperly validated session cookies. Exploitation requires the affected Login V2 UI to be exposed and a target session to be active.

mitigation

Upgrade ZITADEL to version 4.19.2 or later. Until the upgrade is complete, restrict access to the Login V2 UI to trusted networks where feasible and monitor for suspicious session activity.

fixed in 4.19.2

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.
0.42%35th percentile
agent run time
21m
cve.org record, t = 0The moment cve.org publishes the CVE in full.
2026-10-12 16:05Z
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. 2026-10-12 16:05Z
    cve_org: trigger signal, started the run

this entry in the feed

GET /api/v1/feed/CVE-2026-109373

{
  "etk_id": "ETK-2026-1387",
  "cve_id": "CVE-2026-109373",
  "display_id": "CVE-2026-109373",
  "ghsa_id": "GHSA-ff7c-8692-c559",
  "euvd_id": "EUVD-2026-97671",
  "status": "published",
  "anchor_state": "anchored",
  "title": "Authentication bypass in ZITADEL Login V2",
  "summary": "ZITADEL versions 3.0.0 through 4.19.1 are affected by an authentication bypass in the Login V2 UI. An unauthenticated attacker may obtain session tokens and take over user accounts, including administrator accounts, by abusing improperly validated session cookies. Exploitation requires the affected Login V2 UI to be exposed and a target session to be active.",
  "mitigation": "Upgrade ZITADEL to version 4.19.2 or later. Until the upgrade is complete, restrict access to the Login V2 UI to trusted networks where feasible and monitor for suspicious session activity.",
  "vendor": "zitadel",
  "product": "zitadel",
  "affected": [
    {
      "affected_notes": [
        "4.0.0 - 4.19.1"
      ],
      "affected_ranges": [],
      "ecosystem": "zitadel",
      "fixed_versions": [
        "4.19.2"
      ],
      "package_name": "ZITADEL",
      "purl": null
    },
    {
      "affected_notes": [
        "3.0.0 - 3.4.15"
      ],
      "affected_ranges": [],
      "ecosystem": "zitadel",
      "fixed_versions": [],
      "package_name": "ZITADEL",
      "purl": null
    }
  ],
  "cwes": [
    441
  ],
  "cvss_score": 9.2,
  "cvss_src": "cna_vendor",
  "cvss_vector": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
  "epss_score": 0.0042,
  "epss_percentile": 0.3547,
  "epss_asof": "2026-10-21",
  "automation": "deterministic",
  "check": true,
  "check_confidence_basis": "differential",
  "exploit": false,
  "pipeline_minutes": 20.90156455,
  "t0_at": "2026-10-12T16:05:45.649000+00:00",
  "signals": {
    "check": {
      "at": "2026-10-12T17:27:19.891420+00:00",
      "days": 0.05664632430555556,
      "is_lower_bound": false,
      "measured_at": "2026-10-12T16:05:45.649000+00:00",
      "url": null
    },
    "trigger_signal": {
      "at": "2026-10-12T16:05:45.649000+00:00",
      "days": 0,
      "is_lower_bound": false,
      "measured_at": "2026-10-12T16:05:45.649000+00:00",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-109373"
    }
  }
}

published 2026-10-12 17:06Z
last change 2026-10-21 21:36Z

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