CVE-2026-89425
UTF8DataInputJsonParser._reportInvalidToken() in FasterXML jackson-core builds the offending-token text for its error message by appending Java identifier characters to a StringBuilder in a loop that has no upper bound. Unlike the three sibling parser implementations, including UTF8StreamJsonParser, it never consults ErrorReportConfiguration.getMaxErrorTokenLength() (default 256). A malformed token supplied to a parser created through JsonFactory.createParser(DataInput) is therefore accumulated in full. No StreamReadConstraints setting mitigates this: maxDocumentLength cannot be applied to DataInput sources at all, and maxStringLength does not cover this path because the accumulation bypasses ReadConstrainedTextBuffer. The reporter measured a 20,000,109-character exception message from a 20-million-character malformed token on the DataInput path, against 367 characters for identical input on the InputStream path. Scaling the payload drives the StringBuilder, which also incurs byte-to-char expansion and internal array doubling, to many times the raw payload size and can trigger OutOfMemoryError for the whole JVM. UTF8DataInputJsonParser was introduced in 2.8.0 together with createParser(DataInput); releases before 2.8.0 do not contain the affected class.
- Score
- CVSS 3.1 7.5 High
- Status
- Deferred - 36c7be3b-2937-45df-85ea-ca7133ea542c
- Published
- 2026-09-23
- Last modified
- 2026-09-23
- Weaknesses
- CWE-400, CWE-770
Affected products
References
- https://github.com/FasterXML/jackson-core/pull/1698
- https://github.com/FasterXML/jackson-core/security/advisories/GHSA-7hhh-6rmp-j9qf