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VULNERABILITIES

CVE-2026-109778 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

Description

Privilege escalation in the WebExtensions component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.

Metrics

CVSS 3.x Severity and Vector Strings:

NDDVolerionCVSS-B:7.1 HIGHVector:CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
CNA: CISA-ADPCVSS-B:8.8 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://bugzilla.mozilla.org/show_bug.cgi?id=2070547 [email protected]Issue TrackingPermission RequiredVendor
https://www.mozilla.org/security/advisories/mfsa2026-106/ [email protected]AdvisoryBundleVendor
https://www.mozilla.org/security/advisories/mfsa2026-108/ [email protected]AdvisoryBundleVendor
https://www.mozilla.org/security/advisories/mfsa2026-109/ [email protected]AdvisoryBundleVendor
https://www.mozilla.org/security/advisories/mfsa2026-110/ [email protected]AdvisoryBundleVendor

Weakness Enumeration

CWE-IDCWE NameSource
CWE-269Improper Privilege ManagementCISA-ADP

Affected Products

ProductVersions
Mozilla Firefox
All versions

CPE

  • cpe:2.3:a:mozilla:firefox:*:*:*:*:*:*:*:*

Remediation

  • Upgrade: 158moderate effort
Mozilla Firefox ESR
All versions

CPE

  • cpe:2.3:a:mozilla:firefox_esr:*:*:*:*:*:*:*:*

Remediation

  • Upgrade: 153.5moderate effort
Mozilla Thunderbird
All versions

CPE

  • cpe:2.3:a:mozilla:thunderbird:*:*:*:*:*:*:*:*

Remediation

  • Upgrade: 158moderate effort
  • Upgrade: 153.5moderate effort

Change History

4 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-109778
NVD Published Date:
Oct 13, 2026
NVD Last Modified:
Oct 14, 2026
Source:
[email protected]