CVE-2023-6871

mediumpriority · track · 17EPSS 0.005 · 42 %ileDEEURUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.49% (42nd) EPSS

CVSS 4.3 · medium

Is it mine?

33 products

Check your exposure

Who says so?

4 sources

cnnvd · enisa_euvd · fstec_bdu · cert_bund

EPSS · scored 2026-10-27

Under certain conditions, Firefox did not display a warning when a user attempted to navigate to a new protocol handler. This vulnerability affects Firefox < 121.

cvss

Technical severity, 0–10. One row per scoring source.

4.3

010

base score 0–10 · higher = more severe · hover a vector to decode

v3.14.3mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:Nprimary · NVD / NIST USexploitability 2.8 · impact 1.4

v3.14.3mediumAV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:Nsecondary · FSTEC (BDU) RU

v3.14mediumCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:L/A:N/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-357US

affected products (33)

Products and version ranges known to be affected.

Amazon Linux 2all versionscert_bundDEcpe:/o:amazon:linux_2:-
Debian Linuxall versionscert_bundDEcpe:/o:debian:debian_linux:-
Fedora Linuxall versionscert_bundDEcpe:/o:fedoraproject:fedora:-
Gentoo Linuxall versionscert_bundDEcpe:/o:gentoo:linux:-
IBM QRadar SIEM 7.5all versionscert_bundDEcpe:/a:ibm:qradar_siem:7.5
IGEL OSall versionscert_bundDEcpe:/o:igel:os:-
Mozilla Firefox <121all versionscert_bundDE
Mozilla Firefox <ESR 115.6all versionscert_bundDE
Mozilla Thunderbird <115.6all versionscert_bundDE
Open Source CentOSall versionscert_bundDEcpe:/o:centos:centos:-
Oracle Linuxall versionscert_bundDEcpe:/o:oracle:linux:-
RESF Rocky Linuxall versionscert_bundDEcpe:/o:resf:rocky_linux:-
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
Red Hat OpenShift Container Platform 4.11all versionscert_bundDEcpe:/a:redhat:openshift:container_platform_4.11
Red Hat OpenShift Container Platform 4.12all versionscert_bundDEcpe:/a:redhat:openshift:container_platform_4.12
Red Hat OpenShift Container Platform 4.9all versionscert_bundDEcpe:/a:redhat:openshift:container_platform_4.9
Red Hat OpenShift container platform 4.10all versionscert_bundDEcpe:/a:redhat:openshift:container_platform_4.10
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
SUSE openSUSEall versionscert_bundDEcpe:/o:suse:opensuse:-
Ubuntu Linuxall versionscert_bundDEcpe:/o:canonical:ubuntu_linux:-

showing 20 of 33

advisories (1)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2023-3185Mozilla Firefox und Thunderbird: Mehrere SchwachstellenDeutsch2023-12-19csaf · cert_bundDE
Ein entfernter, anonymer Angreifer kann mehrere Schwachstellen in Mozilla Firefox, Firefox ESR und Thunderbird ausnutzen, um beliebigen Programmcode auszuführen, Sicherheitsvorkehrungen zu umgehen, Informationen offenzulegen und undefiniertes Verhalten zu verursachen.

also known as (4)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd fstec_bdu cert_bund NVD CVE.org MITRE

published 2023-12-19modified 2026-06-17

references (15)

External citations — patches, advisories, analysis.

scry

Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.

Free scan