# CVE-2026-68496: FasterXML jackson-dataformats-binary Smile parser name length validation bypass

Source: https://junglewise.ai/threats/cve-2026-68496-the-smile-parser-in-fasterxml-jackson-dataformats-binary-never  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-01. Updated: 2026-10-05  
License: CC BY 4.0 with a link back

CVE-2026-68496 · Severity: high · CVSS 7.5 · Published 2026-10-01

FasterXML jackson-dataformats-binary is a Java library that parses binary data formats including Smile. The Smile parser fails to enforce configured name length limits, allowing an attacker to submit a Smile document with an extremely long property name that exhausts server memory and causes a denial of service. No authentication or special privileges are required—just the ability to send data to a parsing endpoint.

Vendors: [FasterXML](https://junglewise.ai/threats/vendors/fasterxml).

## Quick answers

**Is CVE-2026-68496 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-68496 being exploited in the wild.

**How severe is CVE-2026-68496?** High severity, with a CVSS score of 7.5, published 1 October 2026.

**Which products and versions are affected?** FasterXML Jackson-Dataformats-Binary before 2.16.0 (constraint not present); 2.16.0 and later (constraint not enforced in Smile parser).

**Is there a fix for CVE-2026-68496?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-68496 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-68496?** Check whether you run FasterXML Jackson-Dataformats-Binary at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The SmileParser._handleLongFieldName() method grows its internal name buffer without invoking StreamReadConstraints.validateNameLength(), bypassing the configured maxNameLength limit. An unconstrained _growArrayTo() call permits unbounded name buffering, and since maxDocumentLength is also disabled by default, an attacker can craft a Smile document with a property name limited only by upload capacity and available heap. This gap affects binary formats and is specific to the Smile parser; jackson-core's JSON parsers enforce the constraint incrementally.

## Affected products

- FasterXML jackson-dataformats-binary before 2.16.0 (constraint not present); 2.16.0 and later (constraint not enforced in Smile parser)

## Timeline

- 2026-10-01: disclosed

## Related threats

- [FasterXML jackson-dataformats-binary CBOR parser unbounded name length denial of service](https://junglewise.ai/threats/cve-2026-68495-the-cbor-parser-in-fasterxml-jackson-dataformats-binary-never)