CVE-2018-16395
No exploitation reported by the sources we read.
- Published2018-11-16
Am I affected?
Debian, Ubuntu or Red Hat sometimes backport a fix without changing the upstream version number: such a version reads « to verify », never « affected ».With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.
Description
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.
Timeline
dates in UTC- 2018-11-1618:29CVE publishedNVD
- 2026-10-2319:23EPSS crossed 10 %FIRST EPSS
Observed activity
isMalicious corpus · updated 2026-10-23 18:48 UTCBlock these indicators
- Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-16395?format=txt
- CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-16395?format=csv
- TAXII collection of exploited CVEs
- The EDL and CSV take an API key on the Pro plan.
Versions per branch
NVD · OSV| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 14.4 | = 14.04 | no fix published | NVD |
| 16.4 | = 16.04 | no fix published | NVD |
| 18.4 | = 18.04 | no fix published | NVD |
| 18.10 | = 18.10 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.3 | ≥ 2.3.0, ≤ 2.3.7 | no fix published | NVD |
| 2.4 | ≥ 2.4.0, ≤ 2.4.4 | no fix published | NVD |
| 2.5 | ≥ 2.5.0, ≤ 2.5.1 | no fix published | NVD |
| 2.6 | = 2.6.0 | no fix published | NVD |
| Branch | Affected | Fixed in | Source |
|---|---|---|---|
| 2.1 | < 2.1.2 | 2.1.2 | NVD |
| 2.1 | ≥ 2.1.0, < 2.1.2 | 2.1.2 | OSV |
| 2.0 | < 2.0.9 | 2.0.9 | OSV |
2 more products in the sources.
as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.
Fix
Advisories and patches
- hackerone.comPatch
- www.ruby-lang.orgMitigation · Vendor Advisory
- www.ruby-lang.orgRelease Notes · Vendor Advisory
- www.ruby-lang.orgRelease Notes · Vendor Advisory
- www.ruby-lang.orgRelease Notes · Vendor Advisory
- www.ruby-lang.orgRelease Notes · Vendor Advisory
Detection
- Nuclei template
- none so far ProjectDiscovery
- Exploit-DB
- no entry Exploit-DB
- Proof-of-concept repositories
- none listed PoC-in-GitHub
Sources
- NVDCVSS 3.09.8read 2026-10-23
- NVDCVSS 2.07.5read 2026-10-23
- FIRST EPSSEPSS score10.7 %read 2026-10-23
- OSVaffected packages—
Technical details
- CVSS v3 Vector
- CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Published
- 2018-11-16
- Last Modified
- 2026-06-17
- NVD status
- Modified
Frequently asked questions
What is CVE-2018-16395?
Is CVE-2018-16395 actively exploited?
What is the CVSS score for CVE-2018-16395?
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Related vulnerabilities
Same product first, then the same vendor advisory and the same publication week.