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CVE-2026-109750

Status: DeferredCritical (9.6)—
Severity9.6Critical · CVSS 3.1
Exploitation probability0.38 %higher than 31% of CVEs
Active exploitationNonot in the CISA catalog
Public exploitNot knownno public code found

Site isolation issue in the DOM: Web Authentication component. This vulnerability was fixed in Firefox 158 and Thunderbird 158.

CVSS

Base score
9.6
Version
3.1
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days
0.38 %
Percentile among all scored CVEs
31
Score date
10/21/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

ATT&CK techniques

How this vulnerability is exploited and what the attacker gains, in MITRE ATT&CK terms.

El vector UI:R exige interacción del usuario (AV:N, PR:N). T1078 es inferido del componente Web Authentication y del impacto C:H, no del texto, que no detalla credenciales.

Inferred by our analysis agent from the official description, CVSS vector and CWE, and checked by a supervisor. May contain errors.

ATT&CK mitigations that cover these techniques

Application Isolation and SandboxingExploit ProtectionUpdate Software

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Mozilla — FirefoxAI

CWEs

References

Show 3 references

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-109750",
  "cveTags": [],
  "metrics": {
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        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
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          "id": "CVE-2026-109750",
          "role": "CISA Coordinator",
          "options": [
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            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-10-19T20:37:17.777350Z"
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          "attackVector": "NETWORK",
          "baseSeverity": "CRITICAL",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "HIGH"
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  "published": "2026-10-13T13:17:25.887",
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      "url": "https://bugzilla.mozilla.org/show_bug.cgi?id=2067571",
      "source": "security@mozilla.org"
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      "url": "https://www.mozilla.org/security/advisories/mfsa2026-106/",
      "source": "security@mozilla.org"
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      "url": "https://www.mozilla.org/security/advisories/mfsa2026-109/",
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      "value": "Site isolation issue in the DOM: Web Authentication component. This vulnerability was fixed in Firefox 158 and Thunderbird 158."
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  "lastModified": "2026-10-19T21:17:04.920",
  "sourceIdentifier": "security@mozilla.org"
}