CVE-2022-23539 | jsonwebtoken unrestricted key type could lead to legacy keys usage

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. You are affected if you are using an algorithm and a key type other than a combination listed in the GitHub Security Advisory as unaffected. This issue has been fixed, please 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.

Published: 2022-12-23 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2022-23539 is rated Low Risk (31.2/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.06%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-23539

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2023-03-31 0.05% 0.06% +0.01%
2 2023-03-07 0.89% 0.05% -0.84%
3 2022-12-23 0.89%

Full EPSS history (3 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-23539

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.9 3.1 MEDIUM
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:L)
Some sensitive info could get out, but not a total data dump.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
1.6 4.2 [email protected]
8.1 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
2.8 5.2 [email protected]

Weakness enumeration for CVE-2022-23539

GitHub Security Advisory for CVE-2022-23539

GHSA-8cf7-32gw-wr33 · Severity: high · Ecosystem: npm — jsonwebtoken unrestricted key type could lead to legacy keys usage

OS Trackers for CVE-2022-23539

vendor priority summary link
redhat medium https://access.redhat.com/security/cve/CVE-2022-23539

Affected software / configurations for CVE-2022-23539

Vendor Product Version Raw CPE
auth0 jsonwebtoken <= 8.5.1 cpe:2.3:a:auth0:jsonwebtoken:*:*:*:*:*:node.js:*:*

References for CVE-2022-23539

cvelogic Threat Intelligence