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

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.

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

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