CVE-2026-109777: Vulnerability in Mozilla Firefox
Description
Information disclosure in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 158, Firefox ESR 153.5, Thunderbird 158, and Thunderbird 153.5.
CVSS v3.1
Score 4.3medium
Affected software
Mozilla
Firefox
Mozilla
Thunderbird
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves information disclosure within the IndexedDB storage component of Mozilla Firefox. It was resolved by Mozilla in Firefox 158 and Firefox ESR 153.5. The flaw could allow an attacker to access data that should be protected by the browser's storage mechanisms. The vendor has published advisories MFSA2026-106 and MFSA2026-108 detailing the issue and its remediation.
Potential Impact
The impact of this vulnerability is limited to unauthorized information disclosure through the IndexedDB storage mechanism in affected Firefox versions prior to 158. There are no reports of active exploitation in the wild. The vulnerability could compromise confidentiality of stored data in the browser.
Mitigation Recommendations
Users and administrators should update Mozilla Firefox to version 158 or later, or Firefox ESR 153.5 or later, to remediate this vulnerability. The vendor has provided official fixes in these versions. No additional mitigation steps are indicated by the vendor advisories.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- mozilla
- Date Reserved
- 2026-10-13T00:49:08.777Z
- State
- PUBLISHED
- Vendor Advisory Urls
- [{"url":"https://www.mozilla.org/security/advisories/mfsa2026-106/","vendor":"Mozilla"},{"url":"https://www.mozilla.org/security/advisories/mfsa2026-108/","vendor":"Mozilla"}]
Threat ID: 6ace2c512cdf04f65661d577
Added to database: 10/13/2026, 13:04:17 UTC
Last enriched: 10/13/2026, 13:19:06 UTC
Last updated: 10/13/2026, 18:57:33 UTC
Views: 7
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