The asynchronous Smile parser (NonBlockingByteArrayParser) uses a raw-binary length prefix taken from untrusted input to allocate a byte[] before the body is read, with no upper bound and no overflow check. On the raw-binary marker 0xFD, _decodeVInt() computes (value << 6) + (i & 0x3F) without the (value >>> 25) != 0 overflow guard present in the blocking SmileParser._readUnsignedVInt, and _startRawBinary then allocates the declared length immediately.
A Smile feed of roughly ten bytes can therefore force an eager allocation of approximately 2 GB, producing an OutOfMemoryError on reactive or asynchronous Smile endpoints. A VInt crafted to overflow int yields a negative length and a NegativeArraySizeException, a RuntimeException that is not a JacksonException and so escapes the parser contract. Either outcome crashes the request or processing thread.
This is the same class of issue as CVE-2020-28491 in the CBOR parser of this library, which was fixed with a LONGEST_NON_CHUNKED_BINARY guard; the asynchronous Smile parser never received the equivalent guard. No privileges or user interaction beyond the ability to submit data for parsing are required.
"}],"value":"The asynchronous Smile parser (NonBlockingByteArrayParser) uses a raw-binary length prefix taken from untrusted input to allocate a byte[] before the body is read, with no upper bound and no overflow check. On the raw-binary marker 0xFD, _decodeVInt() computes (value << 6) + (i & 0x3F) without the (value >>> 25) != 0 overflow guard present in the blocking SmileParser._readUnsignedVInt, and _startRawBinary then allocates the declared length immediately.\n\n\n\nA Smile feed of roughly ten bytes can therefore force an eager allocation of approximately 2 GB, producing an OutOfMemoryError on reactive or asynchronous Smile endpoints. A VInt crafted to overflow int yields a negative length and a NegativeArraySizeException, a RuntimeException that is not a JacksonException and so escapes the parser contract. Either outcome crashes the request or processing thread.\n\n\n\nThis is the same class of issue as CVE-2020-28491 in the CBOR parser of this library, which was fixed with a LONGEST_NON_CHUNKED_BINARY guard; the asynchronous Smile parser never received the equivalent guard. No privileges or user interaction beyond the ability to submit data for parsing are required."}],"impacts":[{"capecId":"CAPEC-130","descriptions":[{"lang":"en","value":"CAPEC-130 Excessive Allocation"}]}],"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-789","description":"CWE-789 Memory Allocation with Excessive Size Value","lang":"en","type":"CWE"}]}],"providerMetadata":{"dateUpdated":"2026-10-28T00:01:44.496Z","orgId":"36c7be3b-2937-45df-85ea-ca7133ea542c","shortName":"HeroDevs"},"references":[{"name":"GHSA-h3c2-2m49-r49w","tags":["vendor-advisory"],"url":"https://github.com/FasterXML/jackson-dataformats-binary/security/advisories/GHSA-h3c2-2m49-r49w"}],"source":{"advisory":"GHSA-h3c2-2m49-r49w","discovery":"EXTERNAL"},"tags":["x_open-source"],"timeline":[{"lang":"en","time":"2026-10-20T22:47:00.000Z","value":"GHSA-h3c2-2m49-r49w published by the maintainer in FasterXML/jackson-dataformats-binary"}],"title":"jackson-dataformat-smile: unbounded eager byte[] allocation for raw binary in the async parser allows OutOfMemoryError denial of service","x_generator":{"engine":"Vulnogram 0.5.0"}}},"cveMetadata":{"assignerOrgId":"36c7be3b-2937-45df-85ea-ca7133ea542c","assignerShortName":"HeroDevs","cveId":"CVE-2026-104895","datePublished":"2026-10-28T00:01:44.496Z","dateReserved":"2026-10-02T15:02:48.774Z","dateUpdated":"2026-10-28T00:01:44.496Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-28 00:17:11","lastModifiedDate":"2026-10-28 15:24:56","problem_types":["CWE-789","CWE-789 CWE-789 Memory Allocation with Excessive Size Value"],"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}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"104895","Ordinal":"1","Title":"jackson-dataformat-smile: unbounded eager byte[] allocation for ","CVE":"CVE-2026-104895","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"104895","Ordinal":"1","NoteData":"The asynchronous Smile parser (NonBlockingByteArrayParser) uses a raw-binary length prefix taken from untrusted input to allocate a byte[] before the body is read, with no upper bound and no overflow check. On the raw-binary marker 0xFD, _decodeVInt() computes (value << 6) + (i & 0x3F) without the (value >>> 25) != 0 overflow guard present in the blocking SmileParser._readUnsignedVInt, and _startRawBinary then allocates the declared length immediately.\n\n\n\nA Smile feed of roughly ten bytes can therefore force an eager allocation of approximately 2 GB, producing an OutOfMemoryError on reactive or asynchronous Smile endpoints. A VInt crafted to overflow int yields a negative length and a NegativeArraySizeException, a RuntimeException that is not a JacksonException and so escapes the parser contract. Either outcome crashes the request or processing thread.\n\n\n\nThis is the same class of issue as CVE-2020-28491 in the CBOR parser of this library, which was fixed with a LONGEST_NON_CHUNKED_BINARY guard; the asynchronous Smile parser never received the equivalent guard. No privileges or user interaction beyond the ability to submit data for parsing are required.","Type":"Description","Title":"jackson-dataformat-smile: unbounded eager byte[] allocation for "}]}}}