CVE-2018-18493

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

Score 9.8 from GitHub Security Advisory (severity: CRITICAL) published 2022-05-14. NVD baseline CVSS 9.8; sources differ by 0.0.

Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, nvd
9.8EG
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS PROB: 5%CVSS: 9.8Exploit: None knownExposed: 0

A fix is available — apply it.

A buffer overflow can occur in the Skia library during buffer offset calculations with hardware accelerated canvas 2D actions due to the use of 32-bit calculations instead of 64-bit. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4, and Firefox < 64.

CVSS v3
9.8
EG Score
9.8(medium)
EG Risk
51(Track)
EG Risk 51/100SSVC: Track

EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).

How it’s computed
Severity98% × 45%
Exploitation5% × 40%
Automatability30% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
5%
EPSS %ILE
92%
KEV
Not listed

Published

February 28, 2019

Last Modified

November 25, 2025

Advisory Details (8)

Auto-updated Aug 20, 2026
Patch available. Sources: redhat.
generic

Mozilla Firefox: Multiple vulnerabilities (GLSA 201903-04) — Gentoo security

https://security.gentoo.org/glsa/201903-04
generic Patch Available

[SECURITY] [DLA 1605-1] firefox-esr security update

https://lists.debian.org/debian-lts-announce/2018/12/msg00002.html
generic

1504452 - (CVE-2018-18493) heap-buffer-overflow write in add_line

https://bugzilla.mozilla.org/show_bug.cgi?id=1504452
redhat Patch Available

Affected: Red Hat Enterprise Linux 7.

https://access.redhat.com/errata/RHSA-2019:0160
redhat Patch Available

Affected: Red Hat Enterprise Linux 6.

https://access.redhat.com/errata/RHSA-2019:0159
redhat Patch Available

Affected: Red Hat Enterprise Linux 7.

https://access.redhat.com/errata/RHSA-2018:3833
redhat Patch Available

Affected: Red Hat Enterprise Linux 6.

https://access.redhat.com/errata/RHSA-2018:3831
generic

CVE-2018-17466 - PSIRT.COM

http://www.securityfocus.com/bid/106168

Patch Availability(6)

Vendor / EcosystemFixed in / PatchReleasedSource
ubuntuxul-ext-lightning (1:60.4.0+build2-0ubuntu0.16.04.1) @ xenial2026-05-27ubuntu
ubuntufirefox-testsuite (64.0+build3-0ubuntu0.16.04.1) @ xenial2026-05-27ubuntu
redhatthunderbird-0:60.4.0-1.el7_62019-01-24redhat
redhatthunderbird-0:60.4.0-1.el62019-01-24redhat
redhatfirefox-0:60.4.0-1.el62018-12-17redhat
redhatfirefox-0:60.4.0-1.el72018-12-17redhat

Patches are aggregated from vendor advisories (Red Hat, Microsoft, Cisco, GitHub) and package ecosystems (OSV, GHSA). Multiple rows for the same upstream release have been deduplicated.

Affected Packages

(12 across 6 ecosystems)
Debian:11(2)
PackageVulnerable rangeFixed inDependents
firefox-esr—60.4.0esr-1—
thunderbird—1:60.4.0-1—
Debian:12(2)
PackageVulnerable rangeFixed inDependents
firefox-esr—60.4.0esr-1—
thunderbird—1:60.4.0-1—
Debian:13(2)
PackageVulnerable rangeFixed inDependents
firefox-esr—60.4.0esr-1—
thunderbird—1:60.4.0-1—
Debian:14(2)
PackageVulnerable rangeFixed inDependents
firefox-esr—60.4.0esr-1—
thunderbird—1:60.4.0-1—
Debian:8(2)
PackageVulnerable rangeFixed inDependents
firefox-esr45.0.1esr-1 ... 60.3.0esr-3 (119 versions)60.4.0esr-1~deb8u1—
thunderbird1.5-4 ... 1:60.3.1-1 (62 versions)1:60.4.0-1~deb8u1—
Debian:9(2)
PackageVulnerable rangeFixed inDependents
firefox-esr45.9.0esr-1 ... 60.4.0esr-1~deb8u1 (82 versions)60.4.0esr-1~deb9u1—
thunderbird1.5-4 ... 1:60.4.0-1~deb8u1 (63 versions)1:60.4.0-1~deb9u1—

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

All Vendor Advisories

(6)

Every vendor that published an advisory referencing this CVE — pulled from our cve_vendor_advisories aggregation. Click any row for the vendor's original advisory page.

Data Freshness Timeline

(refreshed 7× in last 7d / 29× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

Showing the most recent 100 of 123 total refreshes for this CVE.

  1. 2026-08-20 22:51 UTCEPSS rescore
  2. 2026-08-19 17:00 UTCEPSS rescore
  3. 2026-08-18 13:44 UTCEPSS rescore
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  1. 2026-07-24 14:14 UTCEPSS rescore
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  3. 2026-07-23 01:34 UTCEG score recompute
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  5. 2026-07-22 14:05 UTCEPSS rescore
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  7. 2026-07-20 22:02 UTCOSV refresh
  8. 2026-07-20 17:04 UTCEPSS rescore
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  23. 2026-07-09 19:06 UTCEPSS rescore
  24. 2026-07-08 15:11 UTCEPSS rescore
  25. 2026-07-07 13:42 UTCEPSS rescore
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  27. 2026-07-06 16:24 UTCEPSS rescore
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  64. 2026-06-15 05:43 UTCOSV refresh
  65. 2026-06-14 23:15 UTCEPSS rescore
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  75. 2026-06-06 13:45 UTCEPSS rescore

Related CVEs(same vendor + same CWE)

Frequently asked(5)

What is CVE-2018-18493?
CVE-2018-18493 is a critical vulnerability published on February 28, 2019. A buffer overflow can occur in the Skia library during buffer offset calculations with hardware accelerated canvas 2D actions due to the use of 32-bit calculations instead of 64-bit. This results in a potentially exploitable crash. This vulnerability affects Thunderbird < 60.4, Firefox ESR < 60.4,…
When was CVE-2018-18493 disclosed?
CVE-2018-18493 was first published in the National Vulnerability Database on February 28, 2019, with the most recent update on November 25, 2025. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2018-18493 actively exploited?
CVE-2018-18493 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 5% probability of exploitation in the next 30 days, which ranks it in the top 8.5% of all scored CVEs.
What is the CVSS score of CVE-2018-18493?
CVE-2018-18493 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2018-18493?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-18493, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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