CVE-2026-100794Sandbox escape due to incorrect boundary conditions in the Internationalization component
Updated under an hour ago ()
Does this affect you?
It affects Mozilla Thunderbird and 1 other product. Add what you run to find out whether that includes you.
EPSS puts the chance of exploitation in the next 30 days at 0.34%, higher than 26% of scored CVEs.
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Free account, 1 product
Sandbox escape due to incorrect boundary conditions in the Internationalization component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, and Firefox ESR 140.17.
- CVSS
- 9.6 CRITICAL (v3.1, CISA ADP)CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
- Weakness (CWE)
- CWE-119
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- 0.34% (percentile 26)
- Assigned by
- mozilla
- NVD analysis
- Undergoing Analysis
- Record last updated
- Oct 1, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Mozilla Thunderbird mozilla:thunderbird (from the name) | 140.17 builds before 140.* not affected; 153.4 builds before 153.* not affected; from 157 not affected | CNA record |
Mozilla Firefox mozilla:firefox (from the name) | 140.17 builds before 140.* not affected; 153.4 builds before 153.* not affected; from 157 not affected | CNA record |
References
- https://bugzilla.mozilla.org/show_bug.cgi?id=2028871
- https://www.mozilla.org/security/advisories/mfsa2026-100/
- https://www.mozilla.org/security/advisories/mfsa2026-101/
- https://www.mozilla.org/security/advisories/mfsa2026-102/
- https://www.mozilla.org/security/advisories/mfsa2026-103/
- https://www.mozilla.org/security/advisories/mfsa2026-97/
- https://www.mozilla.org/security/advisories/mfsa2026-99/
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.