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.
"}],"value":"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."}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":7.5,"baseSeverity":"HIGH","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-770","description":"CWE-770 Allocation of Resources Without Limits or Throttling","lang":"en","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-400","description":"CWE-400 Uncontrolled Resource Consumption","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-10-01T17:36:57.760Z","orgId":"36c7be3b-2937-45df-85ea-ca7133ea542c","shortName":"HeroDevs"},"references":[{"name":"GHSA-3v8f-v6vx-fmrm","tags":["vendor-advisory"],"url":"https://github.com/FasterXML/jackson-dataformats-binary/security/advisories/GHSA-3v8f-v6vx-fmrm"},{"name":"FasterXML/jackson-dataformats-binary#726","tags":["patch"],"url":"https://github.com/FasterXML/jackson-dataformats-binary/issues/726"},{"name":"CVE-2026-68495 (CBOR parser, same advisory)","tags":["related"],"url":"https://www.cve.org/CVERecord?id=CVE-2026-68495"},{"name":"jackson-dataformats-binary 2.18.10 release notes (maps #725/#726 to CVE IDs)","tags":["release-notes"],"url":"https://github.com/FasterXML/jackson-dataformats-binary/blob/2.18/release-notes/VERSION-2.x"}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Upgrade to com.fasterxml.jackson.dataformat:jackson-dataformat-smile 2.18.10, 2.21.6 or 2.22.2, or to tools.jackson.dataformat:jackson-dataformat-smile 3.1.6 or 3.2.2. The 2.16.x, 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.
"}],"value":"Upgrade to com.fasterxml.jackson.dataformat:jackson-dataformat-smile 2.18.10, 2.21.6 or 2.22.2, or to tools.jackson.dataformat:jackson-dataformat-smile 3.1.6 or 3.2.2. The 2.16.x, 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."}],"title":"jackson-dataformats-binary: Smile parser does not enforce StreamReadConstraints.maxNameLength, enabling memory-exhaustion denial of service","workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"No StreamReadConstraints setting mitigates this: maxNameLength is the control that is not enforced, and maxDocumentLength is disabled by default (-1). Bound request body size ahead of the parser, set StreamReadConstraints.maxDocumentLength explicitly on the SmileFactory, and cap JVM heap so a single document cannot exhaust process memory. Avoid parsing untrusted Smile input where these limits cannot be applied.
"}],"value":"No StreamReadConstraints setting mitigates this: maxNameLength is the control that is not enforced, and maxDocumentLength is disabled by default (-1). Bound request body size ahead of the parser, set StreamReadConstraints.maxDocumentLength explicitly on the SmileFactory, and cap JVM heap so a single document cannot exhaust process memory. Avoid parsing untrusted Smile input where these limits cannot be applied."}]}},"cveMetadata":{"assignerOrgId":"36c7be3b-2937-45df-85ea-ca7133ea542c","assignerShortName":"HeroDevs","cveId":"CVE-2026-68496","datePublished":"2026-10-01T17:36:57.760Z","dateReserved":"2026-07-30T15:20:37.473Z","dateUpdated":"2026-10-01T18:15:54.459Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-01 18:17:27","lastModifiedDate":"2026-10-02 18:44:11","problem_types":["CWE-400","CWE-770","CWE-770 CWE-770 Allocation of Resources Without Limits or Throttling","CWE-400 CWE-400 Uncontrolled Resource Consumption"],"metrics":{"cvssMetricV31":[{"source":"36c7be3b-2937-45df-85ea-ca7133ea542c","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-10-01T18:15:29.774591Z","id":"CVE-2026-68496","options":[{"exploitation":"poc"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"68496","Ordinal":"1","Title":"jackson-dataformats-binary: Smile parser does not enforce Stream","CVE":"CVE-2026-68496","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"68496","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"jackson-dataformats-binary: Smile parser does not enforce Stream"}]}}}