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
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 5%CVSS: 9.8Exploit: NoneExposed: 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)
EPSS
91.2%
KEV
Not listed

Published

February 28, 2019

Last Modified

November 25, 2025

Advisory Details (8)

Auto-updated Jun 6, 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
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.

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 12× in last 7d / 48× 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.

  1. 2026-07-06 16:24 UTCEPSS rescore
  2. 2026-07-06 16:24 UTCEPSS rescore
  3. 2026-07-06 02:20 UTCEPSS rescore
  4. 2026-07-05 02:27 UTCEPSS rescore
  5. 2026-07-04 06:28 UTCEPSS rescore
  6. 2026-07-04 06:28 UTCEPSS rescore
  7. 2026-07-03 17:26 UTCOSV refresh
  8. 2026-07-02 16:54 UTCEPSS rescore
  9. 2026-07-01 15:03 UTCEPSS rescore
  10. 2026-07-01 15:03 UTCEPSS rescore
  11. 2026-06-30 23:20 UTCEPSS rescore
  12. 2026-06-30 23:19 UTCEPSS rescore
  13. 2026-06-28 14:04 UTCEPSS rescore
  14. 2026-06-28 04:53 UTCEPSS rescore
  15. 2026-06-28 04:53 UTCEPSS rescore
  16. 2026-06-27 03:06 UTCEPSS rescore
  17. 2026-06-27 03:06 UTCEPSS rescore
  18. 2026-06-25 13:47 UTCEPSS rescore
  19. 2026-06-25 13:47 UTCEPSS rescore
  20. 2026-06-24 14:02 UTCEPSS rescore
  21. 2026-06-24 14:02 UTCEPSS rescore
  22. 2026-06-23 21:30 UTCEPSS rescore
  23. 2026-06-23 21:30 UTCEPSS rescore
  24. 2026-06-23 21:30 UTCEPSS rescore
  25. 2026-06-21 14:54 UTCEPSS rescore
Show 47 more
  1. 2026-06-21 14:54 UTCEPSS rescore
  2. 2026-06-21 01:57 UTCEPSS rescore
  3. 2026-06-21 01:57 UTCEPSS rescore
  4. 2026-06-19 19:23 UTCEPSS rescore
  5. 2026-06-19 19:23 UTCEPSS rescore
  6. 2026-06-18 17:50 UTCEPSS rescore
  7. 2026-06-18 17:50 UTCEPSS rescore
  8. 2026-06-17 17:50 UTCEPSS rescore
  9. 2026-06-17 17:50 UTCEPSS rescore
  10. 2026-06-16 17:50 UTCEPSS rescore
  11. 2026-06-16 17:50 UTCEPSS rescore
  12. 2026-06-15 17:45 UTCEPSS rescore
  13. 2026-06-15 05:43 UTCOSV refresh
  14. 2026-06-14 23:15 UTCEPSS rescore
  15. 2026-06-14 23:14 UTCEPSS rescore
  16. 2026-06-13 22:58 UTCEPSS rescore
  17. 2026-06-12 23:09 UTCEPSS rescore
  18. 2026-06-12 23:09 UTCEPSS rescore
  19. 2026-06-11 13:57 UTCEPSS rescore
  20. 2026-06-10 22:16 UTCEPSS rescore
  21. 2026-06-10 13:19 UTCEPSS rescore
  22. 2026-06-07 15:22 UTCEPSS rescore
  23. 2026-06-07 15:22 UTCEPSS rescore
  24. 2026-06-06 13:45 UTCEPSS rescore
  25. 2026-06-06 13:45 UTCEPSS rescore
  26. 2026-06-05 22:45 UTCEPSS rescore
  27. 2026-06-05 22:45 UTCEPSS rescore
  28. 2026-06-05 06:08 UTCEPSS rescore
  29. 2026-06-05 06:08 UTCEPSS rescore
  30. 2026-06-04 13:10 UTCEPSS rescore
  31. 2026-06-02 20:11 UTCEPSS rescore
  32. 2026-06-02 20:11 UTCEPSS rescore
  33. 2026-06-01 13:50 UTCEPSS rescore
  34. 2026-06-01 13:50 UTCEPSS rescore
  35. 2026-05-31 22:29 UTCEPSS rescore
  36. 2026-05-31 00:14 UTCEPSS rescore
  37. 2026-05-31 00:14 UTCEPSS rescore
  38. 2026-05-29 13:41 UTCEPSS rescore
  39. 2026-05-28 13:42 UTCEPSS rescore
  40. 2026-05-28 13:42 UTCEPSS rescore
  41. 2026-05-27 22:11 UTCEG score recompute
  42. 2026-05-27 22:11 UTCVendor advisory
  43. 2026-05-27 22:11 UTCGHSA enrichment
  44. 2026-05-27 13:38 UTCEPSS rescore
  45. 2026-05-27 13:38 UTCEPSS rescore
  46. 2026-05-26 13:42 UTCEPSS rescore
  47. 2026-05-26 13:42 UTCEPSS rescore

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 91.2% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
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.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2018-18493

Explore →

Is Your Infrastructure Affected by CVE-2018-18493?

EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.

Start Free Scan →Browse All CVEs