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Critical 10.0Published Aug 18, 2026
CVE-2026-75874Sandbox escape in the Remote Settings Client component
Updated under an hour ago ()
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It affects Mozilla Firefox and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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Sandbox escape in the Remote Settings Client component. This vulnerability was fixed in Firefox 154, Thunderbird 154, Firefox ESR 115.40, Firefox ESR 140.15, Firefox ESR 153.2, Thunderbird 140.15, and Thunderbird 153.2.
- CVSS
- 10.0 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- Weakness (CWE)
- CWE-693
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- mozilla
- NVD analysis
- Modified
- Record last updated
- Sep 1, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Mozilla Firefox mozilla:firefox (from the name) | 115.40 builds before 115.* not affected; 140.15 builds before 140.* not affected; 153.2 builds before 153.* not affected; from 154 not affected | CNA record |
Mozilla Thunderbird mozilla:thunderbird (from the name) | 140.15 builds before 140.* not affected; 153.2 builds before 153.* not affected; from 154 not affected | CNA record |
mozilla firefox mozilla:firefox | before 154.0.0 | NVD |
mozilla thunderbird mozilla:thunderbird | before 154.0 | NVD |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2039972permissions-required
- https://www.mozilla.org/security/advisories/mfsa2026-74/vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2026-78/vendor-advisory
- https://www.mozilla.org/security/advisories/mfsa2026-83/
- https://www.mozilla.org/security/advisories/mfsa2026-84/
- https://www.mozilla.org/security/advisories/mfsa2026-85/
- https://www.mozilla.org/security/advisories/mfsa2026-87/
- https://www.mozilla.org/security/advisories/mfsa2026-88/
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.