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Fencer Vulns
high 7.5

CVE-2016-3956 json

npm Token Leak in npm

published 2016-07-02 10 y ago modified 2026-09-10 1 mo ago also GHSA-m5h6-hr3q-22h5 , EUVD-2018-0293

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
5.5%
EPSS 5.5% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

The CLI in npm before 2.15.1 and 3.x before 3.8.3, as used in Node.js 0.10 before 0.10.44, 0.12 before 0.12.13, 4 before 4.4.2, and 5 before 5.10.0, includes bearer tokens with arbitrary requests, which allows remote HTTP servers to obtain sensitive information by reading Authorization headers.

Patch / fix

  • npm npm 2.15.1, 3.8.3
  • npmjs npm 2.15.1, 3.8.3
  • npm Debian 14, Debian 13, Debian 12 5.8.0+ds-2

debian advisories DEBIAN-CVE-2016-3956

  • npm Ubuntu Pro 16.04 LTS 3.5.2-0ubuntu4.1.16.04.1~esm1
  • npm Ubuntu Pro 18.04 LTS 3.5.2-0ubuntu4.1.18.04.1~esm1

ubuntu advisories UBUNTU-CVE-2016-3956

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2016-3956 updated cvss 4.3

npm: bearer token leak to non-registry hosts

  • Red Hat Software Collections nodejs010-npm
    affected: no fix planned “Will not fix”
  • Red Hat Software Collections rh-nodejs4-npm
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

5.46% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:P/I:N/A:N

Affected packages

ecosystem package affected fixed in
npm npm
<2.15.1
>=3.0.0, <3.8.3
2.15.1
3.8.3

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.