Skip to content
Fencer Vulns
medium 4.3

CVE-2020-26963 json

Repeated calls to the history and location interfaces could have been used to hang the browser.

published 2020-12-09 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-19487

cvss
4.3
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 58%
public exploits
0
none known

Summary

Repeated calls to the history and location interfaces could have been used to hang the browser. This was addressed by introducing rate-limiting to these API calls. 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-2020-26963

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-2020-26963

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

0.85% chance of exploitation in the next 30 days, higher than 58% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 4.3 CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L
NVD 2.0 4.3 AV:N/AC:M/Au:N/C:N/I:N/A:P

Affected products

  • Mozilla Firefox

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.