VULNERABILITY INTELLIGENCE
CVE-2021-43535
CVSS score8.8 HIGH
EPSS probability1.15%
CISA KEVNot currently listed
Published2021-12-08
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
Description
A use-after-free could have occured when an HTTP2 session object was released on a different thread, leading to memory corruption and a potentially exploitable crash. This vulnerability affects Firefox < 93, Thunderbird < 91.3, and Firefox ESR < 91.3.
Weakness classification
- CWE-416: Use After Free
Primary references
- security@mozilla.org — Issue Tracking, Permissions Required, Vendor Advisory
- security@mozilla.org — Mailing List, Third Party Advisory
- security@mozilla.org — Mailing List, Third Party Advisory
- security@mozilla.org — Third Party Advisory
- security@mozilla.org — Issue Tracking, Third Party Advisory
- security@mozilla.org — Vendor Advisory
- security@mozilla.org — Vendor Advisory
- security@mozilla.org — Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Issue Tracking, Permissions Required, Vendor Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Mailing List, Third Party Advisory
- af854a3a-2127-422b-91ae-364da2661108 — Third Party Advisory