CVE-2026-59171

CVSS 5.9 (medium) · published 2026-11-06

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.

Weakness: CWE-400, CWE-770

Source: NVD CVE-2026-59171

References

• https://github.com/stleary/JSON-java/commit/703ac34a55400f9c50889e3d0c778b6d7962e81c
• https://github.com/stleary/JSON-java/commit/ab92bb9088a37f9e346cd1dda66f6a3c40a201e0
• https://github.com/stleary/JSON-java/commit/fce83c91bb229dde472283dea648a9a8955237fd
• https://github.com/stleary/JSON-java/pull/1065
• https://github.com/stleary/JSON-java/pull/1067
• https://github.com/stleary/JSON-java/releases/tag/20260719
• https://github.com/stleary/JSON-java/security/advisories/GHSA-ghc9-756g-vrcv
• https://github.com/stleary/JSON-java/security/advisories/GHSA-ghc9-756g-vrcv

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