CVE-2018-16395

CRITICALNVD 9.89.8—
EchelonGraph scoreMEDIUM confidence

This critical-severity CVE scores 9.8 under NVD CVSS v3. EPSS exploit probability: 4.4%, top 11% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Elevated
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 11%CVSS: 9.8Exploit: NoneExposed: 0

A fix is available — apply it.

An issue was discovered in the OpenSSL library in Ruby before 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.2, and 2.6.x before 2.6.0-preview3. When two OpenSSL::X509::Name objects are compared using ==, depending on the ordering, non-equal objects may return true. When the first argument is one character longer than the second, or the second argument contains a character that is one less than a character in the same position of the first argument, the result of == will be true. This could be leveraged to create an illegitimate certificate that may be accepted as legitimate and then used in signing or encryption operations.

CVSS v3
9.8
EG Score
9.8(medium)
EPSS
95.3%
KEV
Not listed

Published

November 16, 2018

Last Modified

November 21, 2024

Advisory Details (9)

Auto-updated Jun 23, 2026
Patch available. Sources: redhat.
generic Patch Available

[SECURITY] [DLA 1558-1] ruby2.1 security update

https://lists.debian.org/debian-lts-announce/2018/10/msg00020.html
generic

HackerOne

https://hackerone.com/reports/387250
redhat Patch Available

Affected: Red Hat Enterprise Linux 7.5 Extended Update Support.

https://access.redhat.com/errata/RHSA-2019:2565
redhat Patch Available

Affected: Red Hat Enterprise Linux 7.4 Extended Update Support.

https://access.redhat.com/errata/RHSA-2019:1948
redhat Patch Available

Affected: Red Hat Enterprise Linux 7.

https://access.redhat.com/errata/RHSA-2018:3738
redhat Patch Available
https://access.redhat.com/errata/RHSA-2018:3731
redhat Patch Available
https://access.redhat.com/errata/RHSA-2018:3730
redhat Patch Available
https://access.redhat.com/errata/RHSA-2018:3729
generic
http://www.securitytracker.com/id/1042105

Patch Availability(7)

Vendor / EcosystemFixed in / PatchReleasedSource
ubunturuby2.3-tcltk (2.3.1-2~16.04.11) @ xenial2026-05-28ubuntu
redhatruby-0:2.0.0.648-34.el7_52019-08-27redhat
redhatruby-0:2.0.0.648-34.el7_42019-07-30redhat
redhatrh-ruby24-ruby-0:2.4.5-91.el72018-11-29redhat
redhatrh-ruby25-ruby-0:2.5.3-6.el72018-11-29redhat
redhatrh-ruby23-ruby-0:2.3.8-69.el72018-11-29redhat
redhatruby-0:2.0.0.648-34.el7_62018-11-29redhat

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

(1 across 1 ecosystem)
RubyGems(1)
PackageVulnerable rangeFixed inDependents
openssl2.1.0, 2.1.12.1.2—

All Vendor Advisories

(8)

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 9× in last 7d / 42× 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. 2026-07-12 05:43 UTCEPSS rescore
  2. 2026-07-11 08:24 UTCEPSS rescore
  3. 2026-07-09 19:06 UTCEPSS rescore
  4. 2026-07-08 15:11 UTCEPSS rescore
  5. 2026-07-07 13:42 UTCEPSS rescore
  6. 2026-07-07 13:42 UTCEPSS rescore
  7. 2026-07-06 16:24 UTCEPSS rescore
  8. 2026-07-06 16:24 UTCEPSS rescore
  9. 2026-07-06 02:20 UTCEPSS rescore
  10. 2026-07-05 02:27 UTCEPSS rescore
  11. 2026-07-04 06:28 UTCEPSS rescore
  12. 2026-07-03 21:56 UTCOSV refresh
  13. 2026-07-02 16:54 UTCEPSS rescore
  14. 2026-07-01 15:03 UTCEPSS rescore
  15. 2026-07-01 15:03 UTCEPSS rescore
  16. 2026-06-30 23:19 UTCEPSS rescore
  17. 2026-06-30 23:19 UTCEPSS rescore
  18. 2026-06-28 14:04 UTCEPSS rescore
  19. 2026-06-28 04:53 UTCEPSS rescore
  20. 2026-06-28 04:53 UTCEPSS rescore
  21. 2026-06-27 03:06 UTCEPSS rescore
  22. 2026-06-25 13:47 UTCEPSS rescore
  23. 2026-06-25 13:47 UTCEPSS rescore
  24. 2026-06-24 14:02 UTCEPSS rescore
  25. 2026-06-24 14:02 UTCEPSS rescore
Show 46 more
  1. 2026-06-23 21:30 UTCEPSS rescore
  2. 2026-06-22 14:23 UTCEPSS rescore
  3. 2026-06-21 01:57 UTCEPSS rescore
  4. 2026-06-21 01:57 UTCEPSS rescore
  5. 2026-06-18 17:50 UTCEPSS rescore
  6. 2026-06-18 17:50 UTCEPSS rescore
  7. 2026-06-17 17:50 UTCEPSS rescore
  8. 2026-06-17 17:50 UTCEPSS rescore
  9. 2026-06-16 17:50 UTCEPSS rescore
  10. 2026-06-16 17:50 UTCEPSS rescore
  11. 2026-06-15 17:45 UTCEPSS rescore
  12. 2026-06-15 10:13 UTCOSV refresh
  13. 2026-06-14 23:14 UTCEPSS rescore
  14. 2026-06-14 23:14 UTCEPSS rescore
  15. 2026-06-13 22:58 UTCEPSS rescore
  16. 2026-06-13 22:58 UTCEPSS rescore
  17. 2026-06-12 23:09 UTCEPSS rescore
  18. 2026-06-11 13:57 UTCEPSS rescore
  19. 2026-06-10 22:16 UTCEPSS rescore
  20. 2026-06-10 13:19 UTCEPSS rescore
  21. 2026-06-07 15:22 UTCEPSS rescore
  22. 2026-06-07 15:22 UTCEPSS rescore
  23. 2026-06-06 13:45 UTCEPSS rescore
  24. 2026-06-06 13:45 UTCEPSS rescore
  25. 2026-06-05 22:45 UTCEPSS rescore
  26. 2026-06-05 22:44 UTCEPSS rescore
  27. 2026-06-05 06:08 UTCEPSS rescore
  28. 2026-06-05 06:08 UTCEPSS rescore
  29. 2026-06-04 13:10 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. 2026-05-31 22:29 UTCEPSS rescore
  34. 2026-05-31 22:28 UTCEPSS rescore
  35. 2026-05-31 00:14 UTCEPSS rescore
  36. 2026-05-31 00:14 UTCEPSS rescore
  37. 2026-05-29 13:41 UTCEPSS rescore
  38. 2026-05-28 13:42 UTCEPSS rescore
  39. 2026-05-28 13:42 UTCEPSS rescore
  40. 2026-05-28 01:02 UTCEG score recompute
  41. 2026-05-28 01:02 UTCVendor advisory
  42. 2026-05-27 13:38 UTCEPSS rescore
  43. 2026-05-27 13:38 UTCEPSS rescore
  44. 2026-05-26 16:01 UTCOSV refresh
  45. 2026-05-26 07:17 UTCEPSS rescore
  46. 2026-05-26 07:17 UTCEPSS rescore

Related CVEs(same vendor)

Frequently asked(5)

What is CVE-2018-16395?
CVE-2018-16395 is a critical vulnerability published on November 16, 2018. An issue was discovered in the OpenSSL library in Ruby before 2.3.8, 2.4.x before 2.4.5, 2.5.x before 2.5.2, and 2.6.x before 2.6.0-preview3. When two OpenSSL::X509::Name objects are compared using ==, depending on the ordering, non-equal objects may return true. When the first argument is one…
When was CVE-2018-16395 disclosed?
CVE-2018-16395 was first published in the National Vulnerability Database on November 16, 2018, with the most recent update on November 21, 2024. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2018-16395 actively exploited?
CVE-2018-16395 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 95.3% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2018-16395?
CVE-2018-16395 has a CVSS v3 base score of 9.8 (NVD).
How do I remediate CVE-2018-16395?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2018-16395, 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

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