CVE-2021-43535

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CVSS 3.1

8.8 high

EPSS

1%p64

Published

Dec 8, 2021 (Dec 8, 2021)

Modified

Jun 17, 2026

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.

Vendors: mozilla debian
Products: firefox, firefox esr, thunderbird, debian linux
Weakness: CWE-416
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H

NVD CVE.org GitHub PoCs EPSS (1.1%)

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