CVE-2026-16391: Vulnerability in Mozilla Firefox
Information disclosure in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
AI Analysis
Technical Summary
This vulnerability involves information disclosure in the IndexedDB storage component of Firefox. IndexedDB is a browser feature used for client-side storage of significant amounts of structured data. The flaw could potentially expose stored data to unauthorized parties. Mozilla fixed this issue in Firefox 153 and Firefox ESR 140.13 as part of their July 21, 2026 security updates. The advisory categorizes the impact as moderate and does not report active exploitation. The fix is available and users are advised to update accordingly.
Potential Impact
The vulnerability allows information disclosure from the IndexedDB storage component, potentially exposing sensitive data stored by web applications. The impact is rated moderate by Mozilla. There is no evidence of exploitation in the wild at this time.
Mitigation Recommendations
A fix is available and has been officially released by Mozilla. Users should update to Firefox 153 or later, or Firefox ESR 140.13 or later, to remediate this vulnerability. No additional mitigation steps are indicated by the vendor advisory.
CVE-2026-16391: Vulnerability in Mozilla Firefox
Description
Information disclosure in the Storage: IndexedDB component. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
CVSS v3.1
Score 7.5high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability involves information disclosure in the IndexedDB storage component of Firefox. IndexedDB is a browser feature used for client-side storage of significant amounts of structured data. The flaw could potentially expose stored data to unauthorized parties. Mozilla fixed this issue in Firefox 153 and Firefox ESR 140.13 as part of their July 21, 2026 security updates. The advisory categorizes the impact as moderate and does not report active exploitation. The fix is available and users are advised to update accordingly.
Potential Impact
The vulnerability allows information disclosure from the IndexedDB storage component, potentially exposing sensitive data stored by web applications. The impact is rated moderate by Mozilla. There is no evidence of exploitation in the wild at this time.
Mitigation Recommendations
A fix is available and has been officially released by Mozilla. Users should update to Firefox 153 or later, or Firefox ESR 140.13 or later, to remediate this vulnerability. No additional mitigation steps are indicated by the vendor advisory.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-jvcf-79h8-93pm
- Osv Schema Version
- 1.4.0
- Aliases
- ["CVE-2026-16391"]
- Ecosystems
- []
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a5fd1561010f89cc21c9810
Added to database: 07/21/2026, 20:06:46 UTC
Last enriched: 07/22/2026, 17:41:10 UTC
Last updated: 09/02/2026, 22:52:09 UTC
Views: 63
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