Is CVE-2018-5156 being actively exploited?

CVE-2018-5156 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2018-5156?

CVE-2018-5156 has a CVSS 3.0 base score of 9.8 (CRITICAL).

CVE-2018-5156

CRITICAL · CVSS 9.8EPSS 3.8%EU EUVD

A vulnerability can occur when capturing a media stream when the media source type is changed as the capture is occurring. This can result in stream data being cast to the wrong type causing a potentially exploitable crash. This vulnerability affects Thunderbird < 60, Firefox ESR < 60.1, Firefox ESR < 52.9, and Firefox < 61.

Key facts

CVSS score: 9.8 (v3.0)
Severity: CRITICAL
CVSS vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-20
EPSS score: 3.8% (90th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2018-16942)
Published: October 18, 2018
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2018-16942 in the EU Vulnerability Database. Last updated in EUVD on August 5, 2024.

View on the EU Vulnerability Database

Affected products

canonical / ubuntu linux
canonical / ubuntu linux
canonical / ubuntu linux
canonical / ubuntu linux
debian / debian linux
debian / debian linux
mozilla / firefox
mozilla / thunderbird
redhat / enterprise linux desktop
redhat / enterprise linux desktop
redhat / enterprise linux server
redhat / enterprise linux server
redhat / enterprise linux server aus
redhat / enterprise linux server eus
redhat / enterprise linux server eus
redhat / enterprise linux server tus
redhat / enterprise linux workstation
redhat / enterprise linux workstation

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

Red Hat Enterprise Linux 7.6 - Red Hat, Inc. - Common Criteria CCEVS-VR-VID-11039-2020 - archived

References

http://www.securityfocus.com/bid/104560(Third Party Advisory, VDB Entry)
http://www.securitytracker.com/id/1041193(Third Party Advisory, VDB Entry)
https://access.redhat.com/errata/RHSA-2018:2112(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2018:2113(Third Party Advisory)
https://bugzilla.mozilla.org/show_bug.cgi?id=1453127(Issue Tracking, Permissions Required, Vendor Advisory)
https://lists.debian.org/debian-lts-announce/2018/06/msg00014.html(Mailing List, Third Party Advisory)
https://lists.debian.org/debian-lts-announce/2018/11/msg00011.html(Mailing List, Third Party Advisory)
https://security.gentoo.org/glsa/201810-01(Third Party Advisory)
https://security.gentoo.org/glsa/201811-13(Third Party Advisory)
https://usn.ubuntu.com/3705-1/(Third Party Advisory)
https://www.debian.org/security/2018/dsa-4235(Third Party Advisory)
https://www.debian.org/security/2018/dsa-4295(Third Party Advisory)
https://www.mozilla.org/security/advisories/mfsa2018-15/(Vendor Advisory)
https://www.mozilla.org/security/advisories/mfsa2018-16/(Vendor Advisory)
https://www.mozilla.org/security/advisories/mfsa2018-17/(Vendor Advisory)
https://www.mozilla.org/security/advisories/mfsa2018-19/(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

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