CVE-2026-29062

Summary

The UTF8DataInputJsonParser, which is used when parsing from a java.io.DataInput source, bypasses the maxNestingDepth constraint (default: 500) defined in StreamReadConstraints.

A similar issue was found in ReaderBasedJsonParser.

This allows a user to supply a JSON document with excessive nesting, which can cause a StackOverflowError when the structure is processed, leading to a Denial of Service (DoS).

The related fix for com.fasterxml.jackson.core:jackson-core, CVE-2025-52999, was not fully applied to tools.jackson.core:jackson-core until the 3.1.0 release. It is recommended that 3.0.x users upgrade.

Patches

jackson-core contains a configurable limit for how deep Jackson will traverse in an input document. This check was missing in a few places in tools.jackson.core:jackson-core.

The change is in https://github.com/FasterXML/jackson-core/pull/1554. jackson-core will throw a StreamConstraintsException if the limit is reached.

jackson-databind also benefits from this change because it uses jackson-core to parse JSON inputs.

Workarounds

Users should avoid parsing input files from untrusted sources.

Resources

GHSA-6v53-7c9g-w56r https://nvd.nist.gov/vuln/detail/CVE-2025-52999 https://github.com/FasterXML/jackson-core/pull/1554