Skip to content
Fencer Vulns
high 8.8

CVE-2020-26969 json

Mozilla developers reported memory safety bugs present in Firefox 82.

published 2020-12-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-19493

cvss
8.8
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.2%
EPSS 1.2% chance of exploitation in 30 days, percentile 68%
public exploits
0
none known

Summary

Mozilla developers reported memory safety bugs present in Firefox 82. Some of these bugs showed evidence of memory corruption and we presume that with enough effort some of these could have been exploited to run arbitrary code. This vulnerability affects Firefox < 83.

Patch / fix

  • mozilla firefox 83.0
  • firefox Ubuntu 16.04 LTS 83.0+build2-0ubuntu0.16.04.3
  • firefox Ubuntu 18.04 LTS 83.0+build2-0ubuntu0.18.04.2
  • firefox Ubuntu 20.04 LTS 83.0+build2-0ubuntu0.20.04.1

ubuntu advisories UBUNTU-CVE-2020-26969

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 92.0-1.2

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10600-1

  • firefox Alpine 3.23, Alpine 3.22, Alpine 3.21 +9 more 83.0-r0
  • librewolf Alpine 3.24, Alpine 3.23, Alpine 3.22 +1 more 83.0-r0

alpine advisories ALPINE-CVE-2020-26969

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • firefox Arch Linux 83.0-1

arch linux advisories AVG-1279

Exploit prediction

1.21% chance of exploitation in the next 30 days, higher than 68% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 8.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 9.3 AV:N/AC:M/Au:N/C:C/I:C/A:C

Affected products

  • Mozilla Firefox

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.