| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| StreamReadConstraints.maxNameLength (default 50,000 characters) is intended to bound how much memory a single JSON Object property name can consume while being parsed, independently of the much larger maxStringLength (default 100,000,000 characters) that bounds ordinary string values. For parsers built over character input — Reader, String or char[] sources, all served by ReaderBasedJsonParser — that bound is not applied while the name is being accumulated. The code path instead re-uses the string-value length check, which is roughly 2000x larger by default.
In the character-input slow path, ReaderBasedJsonParser._parseName2() accumulates the name into the TextBuffer and, when a segment fills, calls TextBuffer.finishCurrentSegment(), which validates only maxStringLength. The correct check, StreamReadConstraints.validateNameLength(int), is reached afterwards in CharsToNameCanonicalizer.findSymbol(), once the entire name has been scanned to its closing quote. By that point the full name — up to maxStringLength characters — has already been buffered in memory.
A remote attacker who can have a single sufficiently long JSON Object property name parsed through this path can force allocation on the order of 100,000,000 characters (approximately 200 MB, with segment bookkeeping pushing real peak usage higher) before any StreamConstraintsException is thrown, instead of the approximately 50,000-character (about 100 KB) bound the API promises. Repeating this across concurrent requests can exhaust the heap and crash the process. No authentication or user interaction is required. Because StreamReadConstraints.maxDocumentLength is disabled by default (-1), nothing else bounds the token first, so the issue is exploitable under default configuration.
Byte-input parsers are not affected: UTF8StreamJsonParser, UTF8DataInputJsonParser and the non-blocking (async) parsers re-validate maxNameLength on every growth of the name-decode buffer via ParserBase._growNameDecodeBuffer(), rejecting an oversized name after allocating only tens of kilobytes. Applications are exposed when untrusted JSON is parsed from a String, Reader or char[] — for example an HTTP request body already read into a String — rather than from raw UTF-8 bytes.
This issue affects com.fasterxml.jackson.core:jackson-core from 2.16.0 and tools.jackson.core:jackson-core from 3.0.0. Releases before 2.16.0 are not affected, because StreamReadConstraints.maxNameLength was first introduced in jackson-core 2.16.0. |
| An issue was discovered in FasterXML jackson-databind prior to 2.7.9.4, 2.8.11.2, and 2.9.6. When Default Typing is enabled (either globally or for a specific property), the service has the Oracle JDBC jar in the classpath, and an attacker can provide an LDAP service to access, it is possible to make the service execute a malicious payload. |
| FasterXML jackson-databind 2.x before 2.9.10.8 mishandles the interaction between serialization gadgets and typing, related to org.apache.tomcat.dbcp.dbcp.datasources.SharedPoolDataSource. |
| FasterXML jackson-databind 2.x before 2.9.10.8 mishandles the interaction between serialization gadgets and typing, related to org.docx4j.org.apache.xalan.lib.sql.JNDIConnectionPool. |
| FasterXML jackson-databind 2.x before 2.9.10.6 mishandles the interaction between serialization gadgets and typing, related to br.com.anteros.dbcp.AnterosDBCPDataSource (aka Anteros-DBCP). |
| FasterXML jackson-databind 2.x before 2.9.10.5 mishandles the interaction between serialization gadgets and typing, related to com.sun.org.apache.xalan.internal.lib.sql.JNDIConnectionPool (aka xalan2). |
| FasterXML jackson-databind 2.x before 2.9.10.5 mishandles the interaction between serialization gadgets and typing, related to oadd.org.apache.xalan.lib.sql.JNDIConnectionPool (aka apache/drill). |
| A Polymorphic Typing issue was discovered in FasterXML jackson-databind before 2.9.10. It is related to com.zaxxer.hikari.HikariDataSource. This is a different vulnerability than CVE-2019-14540. |
| SubTypeValidator.java in FasterXML jackson-databind before 2.9.9.2 mishandles default typing when ehcache is used (because of net.sf.ehcache.transaction.manager.DefaultTransactionManagerLookup), leading to remote code execution. |
| An issue was discovered in FasterXML jackson-databind 2.0.0 through 2.9.5. Use of Jackson default typing along with a gadget class from iBatis allows exfiltration of content. Fixed in 2.7.9.4, 2.8.11.2, and 2.9.6. |
| FasterXML jackson-databind 2.x before 2.9.10.4 mishandles the interaction between serialization gadgets and typing, related to org.springframework.aop.config.MethodLocatingFactoryBean (aka spring-aop). |
| FasterXML jackson-databind 2.x before 2.9.10.4 mishandles the interaction between serialization gadgets and typing, related to org.apache.hadoop.shaded.com.zaxxer.hikari.HikariConfig (aka shaded hikari-config). |
| A Polymorphic Typing issue was discovered in FasterXML jackson-databind 2.0.0 through 2.9.10. When Default Typing is enabled (either globally or for a specific property) for an externally exposed JSON endpoint and the service has the p6spy (3.8.6) jar in the classpath, and an attacker can find an RMI service endpoint to access, it is possible to make the service execute a malicious payload. This issue exists because of com.p6spy.engine.spy.P6DataSource mishandling. |
| A Polymorphic Typing issue was discovered in FasterXML jackson-databind before 2.9.10. It is related to net.sf.ehcache.hibernate.EhcacheJtaTransactionManagerLookup. |
| 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. |
| The CBOR 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. CBORParser._decodeLongerName() decodes a definite-length property name with no length check, and CBORParser._decodeChunkedName() delegates to the value-oriented _finishChunkedText() routine, which validates maxStringLength rather than maxNameLength. An attacker who can have a CBOR 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 CBORFactory parsing, directly or through an ObjectMapper configured with the CBOR 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 Smile parser defect in the same vendor advisory, GHSA-3v8f-v6vx-fmrm, which covers both binary formats. The CBOR parser defect (jackson-dataformats-binary issue #725) is CVE-2026-68495; the Smile parser defect (issue #726) is assigned CVE-2026-68496. |
| Forward-reference completion for @JsonIdentityInfo object IDs in FasterXML jackson-databind performs a linear scan of the pending-reference accumulator for every resolved ID. The affected paths are CollectionDeserializer.CollectionReferringAccumulator.resolveForwardReference() and the equivalent implementation in MapDeserializer. When a document first creates N unresolved object-ID references in an identity-enabled collection or map and then defines those same IDs in reverse order, completion performs on the order of N * (N + 1) / 2 identity comparisons, so a shallow document whose size grows linearly causes quadratic CPU work during deserialization. The reporter instrumented equals() calls on the ID class and measured exactly 2,003,000 comparisons at N = 2,000, against zero comparisons in the pending-reference lookup path for an equally sized control in which every reference was already resolved. The input requires no deep nesting and no syntactically unusual JSON. Exploitation requires an application that deserializes attacker-influenced JSON into an identity-enabled collection or map. The fix replaces the repeated linear lookup with a keyed pending-reference structure. |
| TypeDeserializerBase._findDeserializer() in FasterXML jackson-databind caches the resolved deserializer under the raw, attacker-supplied type ID. When name-based polymorphism is configured with a fallback, for example @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), every distinct unrecognized type ID resolves to the same fallback deserializer but is retained as its own key in the _deserializers map. That map has no configurable bound and lives for the lifetime of the type deserializer, so an attacker who can repeatedly supply fresh unknown type IDs causes monotonic memory retention across requests. The reporter observed 10,000 retained entries from 10,000 distinct unknown IDs, against a single entry for a control that repeated one unknown ID the same number of times, isolating attacker-controlled key cardinality from request volume. Exploitation requires an application that enables name-based polymorphism with a defaultImpl or equivalent fallback, accepts attacker-influenced type IDs, and reuses a long-lived ObjectMapper across requests. The fix stops caching fallback resolutions for unrecognized IDs and bounds both the number of cached entries and the length of a cacheable type ID. |
| UTF8DataInputJsonParser._reportInvalidToken() in FasterXML jackson-core builds the offending-token text for its error message by appending Java identifier characters to a StringBuilder in a loop that has no upper bound. Unlike the three sibling parser implementations, including UTF8StreamJsonParser, it never consults ErrorReportConfiguration.getMaxErrorTokenLength() (default 256). A malformed token supplied to a parser created through JsonFactory.createParser(DataInput) is therefore accumulated in full. No StreamReadConstraints setting mitigates this: maxDocumentLength cannot be applied to DataInput sources at all, and maxStringLength does not cover this path because the accumulation bypasses ReadConstrainedTextBuffer. The reporter measured a 20,000,109-character exception message from a 20-million-character malformed token on the DataInput path, against 367 characters for identical input on the InputStream path. Scaling the payload drives the StringBuilder, which also incurs byte-to-char expansion and internal array doubling, to many times the raw payload size and can trigger OutOfMemoryError for the whole JVM. UTF8DataInputJsonParser was introduced in 2.8.0 together with createParser(DataInput); releases before 2.8.0 do not contain the affected class. |
| NumberInput.looksLikeValidNumber() in FasterXML jackson-core pre-validates "stringified numbers" with two regular expressions: PATTERN_FLOAT ([+-]?[0-9]*[\.]?[0-9]+([eE][+-]?[0-9]+)?), present since 2.17.0, and PATTERN_FLOAT_TRAILING_DOT, added in 2.17.2. PATTERN_FLOAT places adjacent quantifiers over the same character class -- an optional [0-9]* run, an optional dot, then a required [0-9]+ run -- so input that ultimately fails to match forces Java's backtracking engine to retry every possible split point of the digit run.
Matching cost therefore grows with the square of the input length.
An attacker who can supply JSON that an application deserializes into a numeric target type reaches this method through jackson-databind's default String-to-number coercion (StdDeserializer and NumberDeserializers for BigDecimal, BigInteger, Double and Float).
Because StreamReadConstraints.maxStringLength defaults to 20,000,000 characters, no constraint bounds the input before it reaches the regex.
Testing by the reporter confirmed O(n^2) growth across five consecutive input-size doublings, with a single 160,000-character string consuming roughly 74 seconds in one call; a small number of concurrent requests of ordinary body size can therefore exhaust a server's request-handling thread pool.
The affected method does not exist before 2.17.0, so 2.16.x and earlier releases are not affected.
The fix replaces both regular expressions with a hand-rolled single-pass scan. |
