Is CVE-2018-18500 being actively exploited?

CVE-2018-18500 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2018-18500?

CVE-2018-18500 has a CVSS 3.0 base score of 9.8 (CRITICAL).

CVE-2018-18500

CRITICAL · CVSS 9.8EPSS 12.7%EU EUVD

A use-after-free vulnerability can occur while parsing an HTML5 stream in concert with custom HTML elements. This results in the stream parser object being freed while still in use, leading to a potentially exploitable crash. This vulnerability affects Thunderbird < 60.5, Firefox ESR < 60.5, and Firefox < 65.

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-416
EPSS score: 12.7% (96th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2018-10225)
Published: February 5, 2019
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2018-10225 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 / firefox esr
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 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://lists.opensuse.org/opensuse-security-announce/2019-07/msg00021.html
http://www.securityfocus.com/bid/106781(Third Party Advisory, VDB Entry)
https://access.redhat.com/errata/RHSA-2019:0218(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2019:0219(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2019:0269(Third Party Advisory)
https://access.redhat.com/errata/RHSA-2019:0270(Third Party Advisory)
https://lists.debian.org/debian-lts-announce/2019/01/msg00025.html(Mailing List, Third Party Advisory)
https://lists.debian.org/debian-lts-announce/2019/02/msg00024.html(Mailing List, Third Party Advisory)
https://security.gentoo.org/glsa/201903-04(Third Party Advisory)
https://security.gentoo.org/glsa/201904-07
https://usn.ubuntu.com/3874-1/(Third Party Advisory)
https://usn.ubuntu.com/3897-1/(Third Party Advisory)
https://www.debian.org/security/2019/dsa-4376(Third Party Advisory)
https://www.debian.org/security/2019/dsa-4392(Third Party Advisory)
https://www.mozilla.org/security/advisories/mfsa2019-01/(Vendor Advisory)
https://www.mozilla.org/security/advisories/mfsa2019-02/(Vendor Advisory)
https://www.mozilla.org/security/advisories/mfsa2019-03/(Vendor Advisory)

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

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