High

jsonwebtoken unrestricted key type could lead to legacy keys usage

  • Disclosed: 22.12.2022
  • Updated: 11.10.2026 10:22

Overview

Versions <=8.5.1 of jsonwebtoken library could be misconfigured so that legacy, insecure key types are used for signature verification. For example, DSA keys could be used with the RS256 algorithm.

Am I affected?

You are affected if you are using an algorithm and a key type other than the combinations mentioned below

Key type algorithm
ec ES256, ES384, ES512
rsa RS256, RS384, RS512, PS256, PS384, PS512
rsa-pss PS256, PS384, PS512

And for Elliptic Curve algorithms:

alg Curve
ES256 prime256v1
ES384 secp384r1
ES512 secp521r1

How do I fix it?

Update to version 9.0.0. This version validates for asymmetric key type and algorithm combinations. Please refer to the above mentioned algorithm / key type combinations for the valid secure configuration. After updating to version 9.0.0, If you still intend to continue with signing or verifying tokens using invalid key type/algorithm value combinations, you’ll need to set the allowInvalidAsymmetricKeyTypes option to true in the sign() and/or verify() functions.

Will the fix impact my users?

There will be no impact, if you update to version 9.0.0 and you already use a valid secure combination of key type and algorithm. Otherwise, use the allowInvalidAsymmetricKeyTypes option to true in the sign() and verify() functions to continue usage of invalid key type/algorithm combination in 9.0.0 for legacy compatibility.

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
npm package jsonwebtoken < 9.0.0 9.0.0

References

CVSS score 8.1/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
Weakness (CWE)
CWE-327
Platform
npm
Package
jsonwebtoken
Disclosed
22.12.2022
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-8cf7-32gw-wr33 - CC BY 4.0

Vulnerability history: jsonwebtoken

All published vulnerabilities of this package (npm package), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
4
First → latest
10.2018 12.2022
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 1
  • High 1
  • Medium 2

Disclosures per year

  1. 2018: 1
  2. 2019: 0
  3. 2020: 0
  4. 2021: 0
  5. 2022: 3
  6. 2023: 0
  7. 2024: 0
  8. 2025: 0
  9. 2026: 0
  1. jsonwebtoken unrestricted key type could lead to legacy keys usage this entry
    High · 8.1 CVE-2022-23539 < 9.0.0 9.0.0
  2. Critical CVE-2015-9235 < 4.2.2 4.2.2

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