Denial-of-Service Vulnerability in Firefox by Mozilla
CVE-2026-100826

6.5MEDIUM

Key Information:

Vendor

Mozilla
Status
Firefox
Thunderbird
Vendor
CVE Published:
29 September 2026

What is CVE-2026-100826?

This vulnerability resides in the StorageManager component of Firefox, which can lead to a denial-of-service attack. It affects versions of Firefox ESR and Firefox that have not been updated to the latest patched releases. Users are encouraged to upgrade to Firefox ESR 153.4 or Firefox 157 to mitigate this risk and benefit from enhanced security measures.

Affected Version(s)

Firefox 153.4

Firefox 157

Thunderbird 153.4

References

https://bugzilla.mozilla.org/show_bug.cgi?id=2059222
https://www.mozilla.org/security/advisories/mfsa2026-100/
https://www.mozilla.org/security/advisories/mfsa2026-101/

CVSS V3.1

Score:
6.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
Required
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

Mozilla
.