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No exploitation reportedFix available

CVE-2018-16471

No exploitation reported by the sources we read.

  • Published2018-11-13
  • Fixed in2.0.6 · 1.6.11
  • WeaknessCWE-79

Am I 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

There is a possible XSS vulnerability in Rack before 2.0.6 and 1.6.11. Carefully crafted requests can impact the data returned by the `scheme` method on `Rack::Request`. Applications that expect the scheme to be limited to 'http' or 'https' and do not escape the return value could be vulnerable to an XSS attack. Note that applications using the normal escaping mechanisms provided by Rails may not impacted, but applications that bypass the escaping mechanisms, or do not use them may be vulnerable.

Timeline

dates in UTC
  1. 2018-11-1323:29CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-10-23 21:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2018-16471?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-16471?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD · OSV
Rack project rack
BranchAffectedFixed in
2.0≥ 2.0.0, < 2.0.62.0.6
1.6≥ 1.6.0, < 1.6.111.6.11
1.6< 1.6.111.6.11
Debian debian linux
BranchAffectedFixed in
8.0= 8.0no fix published

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Fix

  1. Update Rack project rack to 2.0.6 · 1.6.11

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub

Sources

  • NVDCVSS 3.06.1read 2026-10-23
  • NVDCVSS 2.04.3read 2026-10-23
  • CNAweakness (CWE)CWE-79read 2026-10-23
  • NVDweakness (CWE)CWE-79read 2026-10-23
  • FIRST EPSSEPSS score1.9 %2026-10-23
  • OSVaffected packages—

Technical details

CVSS v3 Vector
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Published
2018-11-13
Last Modified
2026-06-17
NVD status
Modified

Frequently asked questions

What is CVE-2018-16471?

There is a possible XSS vulnerability in Rack before 2.0.6 and 1.6.11. Carefully crafted requests can impact the data returned by the `scheme` method on `Rack::Request`. Applications that expect the scheme to be limited to 'http' or 'https' and do not escape the return value could be vulnerable to an XSS attack. Note that applications using the normal escaping mechanisms provided by Rails may not impacted, but applications that bypass the escaping mechanisms, or do not use them may be vulnerable.

Is CVE-2018-16471 actively exploited?

Active exploitation of CVE-2018-16471 has not been confirmed. Its EPSS score was 1.9% on 2026-10-23, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-16471?

CVE-2018-16471 has a CVSS v3 base score of 6.1 (MEDIUM severity), with vector string CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N.

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