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No exploitation reportedFix available

CVE-2018-12121

No exploitation reported by the sources we read.

  • Published2018-11-28
  • Fixed in11.3.0 · 10.14.0 · 8.14.0 · 6.15.0
  • WeaknessCWE-400

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

Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0: Denial of Service with large HTTP headers: By using a combination of many requests with maximum sized headers (almost 80 KB per connection), and carefully timed completion of the headers, it is possible to cause the HTTP server to abort from heap allocation failure. Attack potential is mitigated by the use of a load balancer or other proxy layer.

Timeline

dates in UTC
  1. 2018-11-2817:29CVE publishedNVD
  2. 2026-10-2319:23EPSS crossed 10 %FIRST EPSS

Observed activity

isMalicious corpus · updated 2026-10-23 18:48 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-2018-12121?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2018-12121?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

NVD
Node.js
BranchAffectedFixed in
11.x≥ 11.0.0, < 11.3.011.3.0
10.x≥ 10.0.0, < 10.14.010.14.0
8.x≥ 8.0.0, < 8.14.08.14.0
6.x≥ 6.0.0, < 6.15.06.15.0
Redhat enterprise linux eus
BranchAffectedFixed in
8.1= 8.1no fix published
8.2= 8.2no fix published
8.4= 8.4no fix published
8.6= 8.6no fix published
Redhat enterprise linux server aus
BranchAffectedFixed in
8.2= 8.2no fix published
8.4= 8.4no fix published
8.6= 8.6no fix published

5 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

  1. Update Node.js to 11.3.0 · 10.14.0 · 8.14.0 · 6.15.0

Advisories and patches

Detection

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

Sources

  • CISA-ADPSSVC decisionnone2026-10-08
  • OpenCVESSVC decisionnone—
  • NVDCVSS 3.17.5read 2026-10-23
  • NVDCVSS 2.05read 2026-10-23
  • CNAweakness (CWE)CWE-400read 2026-10-23
  • NVDweakness (CWE)CWE-400read 2026-10-23
  • FIRST EPSSEPSS score10.2 %read 2026-10-23

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
2018-11-28
Last Modified
2026-10-08
NVD status
Modified

Frequently asked questions

What is CVE-2018-12121?

Node.js: All versions prior to Node.js 6.15.0, 8.14.0, 10.14.0 and 11.3.0: Denial of Service with large HTTP headers: By using a combination of many requests with maximum sized headers (almost 80 KB per connection), and carefully timed completion of the headers, it is possible to cause the HTTP server to abort from heap allocation failure. Attack potential is mitigated by the use of a load balancer or other proxy layer.

Is CVE-2018-12121 actively exploited?

Active exploitation of CVE-2018-12121 has not been confirmed. Its EPSS score was 10.2% on 2026-10-22, the estimated probability of exploitation in the next 30 days.

What is the CVSS score for CVE-2018-12121?

CVE-2018-12121 has a CVSS v3 base score of 7.5 (HIGH severity), with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

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