CVE-2026-100820
published 2026-09-29CVE-2026-100820: Privilege escalation in the Address Bar component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4…
PriorityP345high8.8CVSS 3.1
AVNACLPRNUIRSUCHIHAH
EPSS
0.23%
13.2th percentile
Privilege escalation in the Address Bar 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.
Affected
12 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| mozilla | firefox | < Firefox 157 | Firefox 157 |
| mozilla | firefox | < 140.17.0 | 140.17.0 |
| mozilla | firefox | >= 141.0 < 153.4.0 | 153.4.0 |
| mozilla | firefox | >= 154.0.0 < 157.0.0 | 157.0.0 |
| mozilla | firefox_esr | < Firefox ESR 140.17 | Firefox ESR 140.17 |
| mozilla | firefox_esr | < Firefox ESR 153.4 | Firefox ESR 153.4 |
| mozilla | thunderbird | < Thunderbird 157 | Thunderbird 157 |
| mozilla | thunderbird | < Thunderbird 140.17 | Thunderbird 140.17 |
| mozilla | thunderbird | < Thunderbird 153.4 | Thunderbird 153.4 |
| mozilla | thunderbird | < 140.17.0 | 140.17.0 |
| mozilla | thunderbird | >= 141.0 < 153.4.0 | 153.4.0 |
| mozilla | thunderbird | >= 154.0 < 157.0 | 157.0 |
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Mozilla
Mozilla Foundation Security Advisory 2026-101: CVE-2026-100820
vendor_mozilla·CVSS 8.8
CVE-2026-100820 [HIGH] Mozilla Foundation Security Advisory 2026-101: CVE-2026-100820
Mozilla Foundation Security Advisory 2026-101
CVE: CVE-2026-100820
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 157
Mozilla
Mozilla Foundation Security Advisory 2026-99: CVE-2026-100820
vendor_mozilla·CVSS 8.8
CVE-2026-100820 [HIGH] Mozilla Foundation Security Advisory 2026-99: CVE-2026-100820
Mozilla Foundation Security Advisory 2026-99
CVE: CVE-2026-100820
Product: Firefox ESR
Impact: moderate
Fixed in: Firefox ESR 140.17
Mozilla
Mozilla Foundation Security Advisory 2026-100: CVE-2026-100820
vendor_mozilla·CVSS 8.8
CVE-2026-100820 [HIGH] Mozilla Foundation Security Advisory 2026-100: CVE-2026-100820
Mozilla Foundation Security Advisory 2026-100
CVE: CVE-2026-100820
Product: Firefox ESR
Impact: low
Fixed in: Firefox ESR 153.4
Mozilla
Mozilla Foundation Security Advisory 2026-97: CVE-2026-100820
vendor_mozilla·CVSS 8.8
CVE-2026-100820 [HIGH] Mozilla Foundation Security Advisory 2026-97: CVE-2026-100820
Mozilla Foundation Security Advisory 2026-97
CVE: CVE-2026-100820
Product: Firefox
Impact: low
Fixed in: Firefox 157
Mozilla
Mozilla Foundation Security Advisory 2026-102: CVE-2026-100820
vendor_mozilla·CVSS 8.8
CVE-2026-100820 [HIGH] Mozilla Foundation Security Advisory 2026-102: CVE-2026-100820
Mozilla Foundation Security Advisory 2026-102
CVE: CVE-2026-100820
Product: Thunderbird
Impact: moderate
Fixed in: Thunderbird 140.17
Mozilla
Mozilla Foundation Security Advisory 2026-103: CVE-2026-100820
vendor_mozilla·CVSS 8.8
CVE-2026-100820 [HIGH] Mozilla Foundation Security Advisory 2026-103: CVE-2026-100820
Mozilla Foundation Security Advisory 2026-103
CVE: CVE-2026-100820
Product: Thunderbird
Impact: low
Fixed in: Thunderbird 153.4
GHSA
Privilege escalation in the Address Bar component.
ghsa_unreviewed·2026-09-29
CVE-2026-100820 [HIGH] CWE-269 Privilege escalation in the Address Bar component.
Privilege escalation in the Address Bar component. This vulnerability was fixed in Firefox ESR 153.4, Firefox 157, and Firefox ESR 140.17.
No detection rules found.
No public exploits indexed.
No writeups or analysis indexed.
https://bugzilla.mozilla.org/show_bug.cgi?id=2071645https://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/
2026-09-29
Published