---
id: CVE-2026-68496
title: >-
  The Smile parser in FasterXML jackson-dataformats-binary never invokes
  StreamReadConstraints.validateNameLength() when decoding JSON object property
  names, so the maxNameLength limit is not enforced for this format
summary: >-
  The Smile parser in FasterXML jackson-dataformats-binary never invokes
  StreamReadConstraints.validateNameLength() when decoding JSON object property
  names, so the maxNameLength limit is not enforced for this format.
  SmileParser._handleLo…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-400
  - CWE-770
vendor: FasterXML
product: 'com.fasterxml.jackson.dataformat:jackson-dataformat-smile'
affected:
  - >-
    com.fasterxml.jackson.dataformat:jackson-dataformat-smile >= 2.16.0 <=
    2.18.9
  - >-
    com.fasterxml.jackson.dataformat:jackson-dataformat-smile >= 2.19.0 <=
    2.21.5
  - >-
    com.fasterxml.jackson.dataformat:jackson-dataformat-smile >= 2.22.0 <=
    2.22.1
  - 'tools.jackson.dataformat:jackson-dataformat-smile >= 3.0.0 <= 3.1.5'
  - 'tools.jackson.dataformat:jackson-dataformat-smile >= 3.2.0 <= 3.2.1'
published: '2026-10-01'
updated: '2026-10-02'
sourceUpdated: '2026-10-02T18:44:11.270'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-68496'
references:
  - url: >-
      https://github.com/FasterXML/jackson-dataformats-binary/blob/2.18/release-notes/VERSION-2.x
    label: 36c7be3b-2937-45df-85ea-ca7133ea542c
  - url: 'https://github.com/FasterXML/jackson-dataformats-binary/issues/726'
    label: 36c7be3b-2937-45df-85ea-ca7133ea542c
  - url: >-
      https://github.com/FasterXML/jackson-dataformats-binary/security/advisories/GHSA-3v8f-v6vx-fmrm
    label: 36c7be3b-2937-45df-85ea-ca7133ea542c
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-68495'
    label: 36c7be3b-2937-45df-85ea-ca7133ea542c
  - url: >-
      https://github.com/FasterXML/jackson-dataformats-binary/security/advisories/GHSA-3v8f-v6vx-fmrm
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
epss: 0.00561
epssPercentile: 0.46478
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-10-01T18:15:29.774591Z'
ingestedAt: '2026-10-01T18:55:42.376Z'
---

## Overview

The Smile parser in FasterXML jackson-dataformats-binary never invokes StreamReadConstraints.validateNameLength() when decoding JSON object property names, so the maxNameLength limit is not enforced for this format. SmileParser._handleLongFieldName() grows its internal name buffer through an unconstrained _growArrayTo() call and performs no length validation. An attacker who can have a Smile document parsed may therefore embed a single property name of unbounded length; the parser buffers the whole name in memory before returning it, whatever maxNameLength is configured to. Because StreamReadConstraints.maxDocumentLength is also disabled by default, nothing else bounds the name under default settings, so the only limits are the attacker's upload capacity and available heap, leading to memory exhaustion and denial of service. No privileges beyond the ability to submit data to a parsing endpoint are required, and exploitation needs only that the bytes reach SmileFactory parsing, directly or through an ObjectMapper configured with the Smile module. jackson-core's own JSON parsers enforce maxNameLength incrementally during name decoding; this gap is specific to the binary formats. maxNameLength and validateNameLength were introduced in jackson-core 2.16.0, so releases before 2.16.0 do not contain the constraint that is left unenforced. This issue is tracked together with the CBOR parser defect in the same vendor advisory, GHSA-3v8f-v6vx-fmrm, which covers both binary formats. The Smile parser defect (jackson-dataformats-binary issue #726) is CVE-2026-68496; the CBOR parser defect (issue #725) is assigned CVE-2026-68495.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.