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High 8.8Published Jul 21, 2026
CVE-2026-16396Privilege escalation in WebExtensions.
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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Privilege escalation in WebExtensions. This vulnerability was fixed in Firefox 153, Firefox ESR 140.13, Thunderbird 153, and Thunderbird 140.13.
- CVSS
- 8.8 HIGH (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-269
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Not given
- NVD analysis
- Modified
- Record last updated
- Jul 24, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
mozilla firefox mozilla:firefox | before 140.13.0; before 153.0.0 | NVD |
mozilla thunderbird mozilla:thunderbird | before 140.13.0; from 141.0 before 153.0 | NVD |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2047240permissions-required
- https://www.mozilla.org/security/advisories/mfsa2026-68/vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2026-70/vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2026-71/vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2026-72/vendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.