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.
"}]}],"references":[{"url":"https://github.com/FasterXML/jackson-core/security/advisories/GHSA-7hhh-6rmp-j9qf","name":"GHSA-7hhh-6rmp-j9qf","tags":["vendor-advisory"]},{"url":"https://github.com/FasterXML/jackson-core/pull/1698","name":"FasterXML/jackson-core#1698","tags":["patch"]}],"metrics":[{"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}],"cvssV3_1":{"version":"3.1","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH","baseSeverity":"HIGH","baseScore":7.5,"vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}}],"workarounds":[{"lang":"en","value":"No StreamReadConstraints or ErrorReportConfiguration setting mitigates this issue on the affected code path. Where possible, avoid JsonFactory.createParser(DataInput) for attacker-supplied content and use createParser(InputStream), createParser(Reader) or a byte-array overload instead; those parser implementations enforce maxErrorTokenLength correctly. Otherwise, bound input size ahead of the parser and cap JVM heap so that a single request cannot exhaust process memory.","supportingMedia":[{"type":"text/html","base64":false,"value":"No StreamReadConstraints or ErrorReportConfiguration setting mitigates this issue on the affected code path. Where possible, avoid JsonFactory.createParser(DataInput) for attacker-supplied content and use createParser(InputStream), createParser(Reader) or a byte-array overload instead; those parser implementations enforce maxErrorTokenLength correctly. Otherwise, bound input size ahead of the parser and cap JVM heap so that a single request cannot exhaust process memory.
"}]}],"solutions":[{"lang":"en","value":"Upgrade to com.fasterxml.jackson.core:jackson-core 2.18.11, 2.21.7 or 2.22.3, or to tools.jackson.core:jackson-core 3.1.7 or 3.2.3. The 2.8.x through 2.17.x, 2.19.x, 2.20.x and 3.0.x lines received no fix on their own branch and are no longer maintained upstream; consumers of those lines must move forward to a maintained release.","supportingMedia":[{"type":"text/html","base64":false,"value":"Upgrade to com.fasterxml.jackson.core:jackson-core 2.18.11, 2.21.7 or 2.22.3, or to tools.jackson.core:jackson-core 3.1.7 or 3.2.3. The 2.8.x through 2.17.x, 2.19.x, 2.20.x and 3.0.x lines received no fix on their own branch and are no longer maintained upstream; consumers of those lines must move forward to a maintained release.
"}]}],"credits":[{"lang":"en","value":"manqingzhou","type":"finder"}]},"adp":[{"references":[{"url":"https://github.com/FasterXML/jackson-core/security/advisories/GHSA-7hhh-6rmp-j9qf","tags":["exploit"]}],"metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-09-23T13:54:51.050132Z","id":"CVE-2026-89425","options":[{"Exploitation":"poc"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"title":"CISA ADP Vulnrichment","providerMetadata":{"orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","shortName":"CISA-ADP","dateUpdated":"2026-09-23T14:00:42.979Z"}}]}}