CVE-2020-12399

4.4 mediumEPSS 0.7%

Medium (4.4). EPSS 0.7% chance of exploitation in the next 30 days.

NSS has shown timing differences when performing DSA signatures, which was exploitable and could eventually leak private keys. This vulnerability affects Thunderbird < 68.9.0, Firefox < 77, and Firefox ESR < 68.9.

Severity

CVSS 3.1

4.4 medium

CVSS:3.1/AV:L/AC:H/PR:L/UI:R/S:U/C:H/I:N/A:N

EPSS: 0.7% chance of exploitation in the next 30 days; higher than 51% of CVEs (scores of 2026-10-31)
CWE: CWE-203
Published: 2020-07-09
Modified: 2026-06-17
Record from: the NVD, synced 2026-10-19

Affected

debian:debian_linux
mozilla:firefox
mozilla:firefox_esr
mozilla:thunderbird

References

https://bugzilla.mozilla.org/show_bug.cgi?id=1631576
https://lists.debian.org/debian-lts-announce/2020/09/msg00029.html
https://security.gentoo.org/glsa/202007-49
https://usn.ubuntu.com/4421-1/
https://www.debian.org/security/2020/dsa-4726

Check your stack JSON