CVE-2026-100758CWE-284broken-access-control

CVE-2026-100758

Critical · published September 29, 2026

CVSS v3.1
9.6
EPSS
0%
Percentile
22.0
In the wild
Unconfirmed
What it is

Sandbox escape in the DOM: Navigation component. This vulnerability was fixed in Firefox ESR 153.4, Thunderbird 157, Thunderbird 140.17, Thunderbird 153.4, Firefox 157, Firefox ESR 115.42, and Firefox ESR 140.17.

The record
Technical detail
CVSS v3.1
9.6 · CRITICAL
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H
CVSS v4.0
Not supplied
EPSS
0.00304 · 22.0th percentile
Weakness
CWE-284 · Improper Access Control
Published
2026-09-29T17:17Z
Affected products (7)
ProductVersionsFixed in
mozilla/firefox< 115.42.0115.42.0
mozilla/firefox≥ 116.0.0, < 140.17.0140.17.0
mozilla/firefox≥ 141.0.0, < 153.4.0153.4.0
mozilla/firefox≥ 154.0.0, < 157.0.0157.0.0
mozilla/thunderbird< 140.17.0140.17.0
mozilla/thunderbird≥ 141.0, < 153.4.0153.4.0
mozilla/thunderbird≥ 154.0, < 157.0157.0
References (8)
https://bugzilla.mozilla.org/show_bug.cgi?id=2049792 · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-100/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-101/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-102/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-103/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-97/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-98/ · [email protected]https://www.mozilla.org/security/advisories/mfsa2026-99/ · [email protected]
EPSS history
Timeline
  • 01 OCT 03:44Z
    EPSS moved — → 0%
    epss
  • 29 SEP 12:35Z
    Sandbox escape in the DOM: Navigation component
    cvelistv5