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Fencer Vulns
high 7.5

CVE-2016-2821 json

Use-after-free vulnerability in the mozilla::dom::Element class in Mozilla Firefox before 47.0 and Firefox ESR 45.x before 45.2, when conte…

published 2016-06-13 10 y ago modified 2026-06-17 4 mo ago also EUVD-2016-3894

cvss
7.5
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
2.8%
EPSS 2.8% chance of exploitation in 30 days, percentile 86%
public exploits
0
none known

Summary

Use-after-free vulnerability in the mozilla::dom::Element class in Mozilla Firefox before 47.0 and Firefox ESR 45.x before 45.2, when contenteditable mode is enabled, allows remote attackers to execute arbitrary code or cause a denial of service (heap memory corruption) by triggering deletion of DOM elements that were created in the editor.

Patch / fix

  • firefox-esr Debian 14, Debian 13, Debian 12 45.2.0esr-1

debian advisories DEBIAN-CVE-2016-2821

  • firefox Ubuntu 14.04 LTS 47.0+build3-0ubuntu0.14.04.1
  • firefox Ubuntu 16.04 LTS 47.0+build3-0ubuntu0.16.04.1

ubuntu advisories UBUNTU-CVE-2016-2821

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 RHEL 5 45.2.0-1.el5_11
  • firefox RHEL 6 45.2.0-1.el6_8
  • firefox RHEL 7 45.2.0-1.el7_2

red hat advisories RHSA-2016:1217

  • mozilla-nss SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +6 more 3.21.1-35.1
  • mozilla-nspr SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +6 more 4.12-29.1
  • MozillaFirefox SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +6 more 45.2.0esr-45.2
  • firefox-fontconfig SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +6 more 2.11.0-2.1
  • MozillaFirefox-branding-SLED SLES for SAP 11 SP4, SLES 11 SP4, SLES 11 SP3-TERADATA +5 more 45.0-23.10
  • mozilla-nss SLES for SAP 12 SP1, SLES for SAP 12, SLES 12 SP1 +5 more 3.21.1-46.2
  • mozilla-nspr SLES for SAP 12 SP1, SLES for SAP 12, SLES 12 SP1 +5 more 4.12-15.2
  • MozillaFirefox SLES for SAP 12 SP1, SLES for SAP 12, SLES 12 SP1 +5 more 45.2.0esr-75.2

suse advisories SUSE-SU-2016:2061-1SUSE-SU-2016:1799-1SUSE-SU-2016:1691-1

  • firefox-esr openSUSE Tumbleweed 128.5.1-1.1
  • MozillaFirefox openSUSE Tumbleweed 50.1.0-1.1

opensuse advisories openSUSE-SU-2024:14572-1openSUSE-SU-2024:10071-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-2821 updated cvss 5.1

Mozilla: Use-after-free deleting tables from a contenteditable document (MFSA 2016-51)

  • Red Hat Enterprise Linux (v. 5 server) firefox 45.2.0-1.el5_11 Red Hat Enterprise Linux Client (v. 7) firefox 45.2.0-1.el7_2 Red Hat Enterprise Linux Client Optional (v. 7) firefox 45.2.0-1.el7_2 Red Hat Enterprise Linux Desktop (v. 5 client) firefox 45.2.0-1.el5_11 Red Hat Enterprise Linux Desktop (v. 6) firefox 45.2.0-1.el6_8 Red Hat Enterprise Linux Desktop Optional (v. 6) firefox 45.2.0-1.el6_8
    +9 more products
    Red Hat Enterprise Linux HPC Node Optional (v. 6) firefox 45.2.0-1.el6_8 Red Hat Enterprise Linux Server (v. 6) firefox 45.2.0-1.el6_8 Red Hat Enterprise Linux Server (v. 7) firefox 45.2.0-1.el7_2 Red Hat Enterprise Linux Server Optional (v. 6) firefox 45.2.0-1.el6_8 Red Hat Enterprise Linux Server Optional (v. 7) firefox 45.2.0-1.el7_2 Red Hat Enterprise Linux Workstation (v. 6) firefox 45.2.0-1.el6_8 Red Hat Enterprise Linux Workstation (v. 7) firefox 45.2.0-1.el7_2 Red Hat Enterprise Linux Workstation Optional (v. 6) firefox 45.2.0-1.el6_8 Red Hat Enterprise Linux Workstation Optional (v. 7) firefox 45.2.0-1.el7_2
    fixed: vendor fix RHSA-2016:1217
  • Red Hat Enterprise Linux 5 thunderbird Red Hat Enterprise Linux 6 thunderbird Red Hat Enterprise Linux 7 thunderbird
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

2.77% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 7.5 CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H
NVD 2.0 6.8 AV:N/AC:M/Au:N/C:P/I:P/A:P

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.