light-oauth2 missing public key verification

published 2023-10-24 3 y ago modified 2026-06-17 4 mo ago also GHSA-mx47-h5fv-ghwh , EUVD-2023-2786

cvss: 5.9; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.7%; EPSS 0.7% chance of exploitation in 30 days, percentile 52%
public exploits: 0; none known

light-oauth2 before version 2.1.27 obtains the public key without any verification. This could allow attackers to authenticate to the application with a crafted JWT token.

Patch / fix

fixed in 2

maven com.networknt:light-oauth2 2.1.27
networknt light-oauth2 2.1.27

CISA SSVC

Exploitation: Proof of concept is public
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-09-11)

Exploit prediction

0.69% chance of exploitation in the next 30 days, higher than 52% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/KANIXB/JWTIssues/blob/main/Certification%20Verification%20issue%20in%20light-oauth2.md referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N
GitHub	3.1	5.9	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

Affected packages

ecosystem	package	affected	fixed in
maven	com.networknt:light-oauth2	<2.1.27	2.1.27

Classification

Weakness

CWE-295 Improper Certificate Validation
CWE-347 Improper Verification of Cryptographic Signature

References

github.com /KANIXB/JWTIssues/blob/main/Certification%20Verification%20issue%20in%20light-oauth2.md
web, exploit
github.com /networknt/light-oauth2/issues/369
web, issue-tracking
nvd.nist.gov /vuln/detail/CVE-2023-31580
advisory
github.com /networknt/light-oauth2
package

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.

Summary