Is there a public exploit for CVE-2026-59171?

No public exploit for CVE-2026-59171 was found in Exploit-DB, Metasploit, Nuclei templates or public proof-of-concept repositories. That is an absence of evidence rather than proof that none exists.

How severe is CVE-2026-59171?

CVE-2026-59171 scores CVSS 5.9 (v3.1), rated medium.

What does CVE-2026-59171 affect?

CVE-2026-59171 affects stleary JSON-java.

5.9 Medium

JSON-java is a reference implementation of a JSON package in Java.

CVE-2026-59171

JSON-java is a reference implementation of a JSON package in Java. From version 20150729 through 20260522, JSONTokener.nextSimpleValue can accumulate unbounded numeric tokens before JSONObject.stringToNumber passes them to BigInteger or BigDecimal conversion without a length limit. An application that parses attacker-controlled JSON or XML through JSONObject, JSONArray, or XML.toJSONObject can spend super-linear CPU time converting a sufficiently long numeric literal, blocking request-handling threads and causing denial of service. Strict mode and keep-strings settings in JSONParserConfiguration do not prevent the affected conversion path. Version 20260719 limits numeric conversion length.

Assessment

CVSS: 5.9 (v3.1)
Severity: Medium
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 6 November 2026
Last updated: 6 November 2026
Affected: stleary · JSON-java
Assigner: GitHub_M

CVSS vectorCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

At the source

EUVD (ENISA)

References

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