CVE-2026-110879
CriticalCVSS 9.8Summary
A vulnerability in jackson-databind allows bypassing generic-argument validation: only the outer class of a type ID is checked, while attacker-selected classes inside generic arguments are accepted. This enables deserialization of dangerous classes (e.g., HashMap<FileSystemXmlApplicationContext,String>) even with a validator enabled, potentially leading to remote code execution. Affects versions 2.10.0+ and 3.0.0+; it is an incomplete fix for CVE-2026-54512.
Risk Assessment
Organizations may be exposed to remote code execution (RCE) via crafted JSON if the application uses Jackson default typing or @JsonTypeInfo(use = Id.CLASS). With Spring on the classpath, an attacker can execute arbitrary commands under the application account.
Recommendation
Update jackson-databind to a version containing the complete fix (beyond 2.10.0/3.0.0 – check the latest release) or use a stricter type validator (e.g., BasicPolymorphicTypeValidator) instead of LaissezFaireSubTypeValidator. Avoid class-name default typing and restrict allowed types to the necessary minimum.
Other vulnerabilities in jackson-databind
See all- CVE-2021-20190High
A flaw in jackson-databind before 2.9.10.7 mishandles the interaction between serialization gadgets and typing. The highest threat is to data confidentiality, integrity, and system availability.
- CVE-2020-11620High
FasterXML jackson-databind 2.x before 2.9.10.4 mishandles the interaction between serialization gadgets and typing, related to org.apache.commons.jelly.impl.Embedded (aka commons-jelly). This may allow an attacker to perform dangerous operations during deserialization.
- CVE-2019-14893Critical
A flaw was discovered in FasterXML jackson-databind in all versions before 2.9.10 and 2.10.0, where it would permit polymorphic deserialization of malicious objects using the xalan JNDI gadget when used in conjunction with polymorphic type handling methods such as `enableDefaultTyping()` or when @JsonTypeInfo is using `Id.CLASS` or `Id.MINIMAL_CLASS` or in any other way which ObjectMapper.readValue might instantiate objects from unsafe sources. An attacker could use this flaw to execute arbitrary code.
- CVE-2019-14892Critical
A flaw was discovered in jackson-databind in versions before 2.9.10, 2.8.11.5 and 2.6.7.3, which would permit polymorphic deserialization of a malicious object using commons-configuration 1 and 2 JNDI classes. An attacker could use this flaw to execute arbitrary code.
- CVE-2020-9547Critical
FasterXML jackson-databind 2.x before 2.9.10.4 mishandles the interaction between serialization gadgets and typing, related to com.ibatis.sqlmap.engine.transaction.jta.JtaTransactionConfig (aka ibatis-sqlmap).
- CVE-2020-8840Critical
FasterXML jackson-databind 2.0.0 through 2.9.10.2 lacks certain xbean-reflect/JNDI blocking, as demonstrated by org.apache.xbean.propertyeditor.JndiConverter. This may allow remote code execution.
- CVE-2019-20330Critical
FasterXML jackson-databind 2.x before 2.9.10.2 lacks certain net.sf.ehcache blocking. This may allow an attacker to abuse polymorphic deserialization to perform dangerous operations.
- CVE-2019-17531Critical
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 apache-log4j-extra (version 1.2.x) jar in the classpath, and an attacker can provide a JNDI service to access, it is possible to make the service execute a malicious payload.
- CVE-2019-17267Critical
A Polymorphic Typing issue was discovered in FasterXML jackson-databind before 2.9.10. It is related to net.sf.ehcache.hibernate.EhcacheJtaTransactionManagerLookup.
- CVE-2019-16943Critical
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, an attacker can find an RMI service endpoint to access and make the service execute a malicious payload. This issue exists because of com.p6spy.engine.spy.P6DataSource mishandling.
Original NVD description (English source)
jackson-databind validates the outer class of a class-name type ID but accepts attacker-selected classes inside its generic arguments, even when those classes violate the declared type or would be rejected as direct type IDs. This bypasses the generic-argument validation added for CVE-2026-54512 (GHSA-j3rv-43j4-c7qm), of which this is an incomplete fix. DatabindContext._resolveAndValidateGeneric() checks the outer class against the declared base type and then passes each argument from the type ID to _validateTypeParameter(), which validates the argument against the outer base type rather than enforcing its corresponding declared generic binding. It also invokes validators with arguments that have not passed the subtype check those validators expect. Under the default DefaultBaseTypeLimitingValidator this accepts an unrelated class inside a generic subtype even when the same class is rejected as a direct type ID. Where an allowIfBaseType(...) rule approves the outer type, Jackson substitutes LaissezFaireSubTypeValidator, so the configured validator no longer restricts the embedded arguments. The element type of a plain array type ID such as [Lpkg.Gadget; is likewise left unvalidated once the array's base type is approved. Affected paths include annotation-based class-name polymorphism with a default Jackson 3.x JsonMapper, configured default typing in both Jackson 2.x and 3.x, and integrations that expose that default typing. The default-validator case requires no application-authored validator: with @JsonTypeInfo(use = Id.CLASS), a direct gadget type ID is rejected as "Not a subtype", while a type ID naming a generic wrapper around the same gadget is accepted and deserialized, including attacker-supplied bean properties. Where class-name default typing permits Map, a property declared as Map<String,String> accepts HashMap<FileSystemXmlApplicationContext,String>; map-key discovery then passes the attacker-controlled JSON property name to the selected class's one-string constructor. With Spring on the classpath and attacker-controlled XML the application can load, that constructor loads the XML and invokes ProcessBuilder.start() under the application account, giving arbitrary command execution. This issue affects com.fasterxml.jackson.core:jackson-databind from 2.10.0 and tools.jackson.core:jackson-databind from 3.0.0. Releases before 2.10.0 are not affected, because PolymorphicTypeValidator was introduced in jackson-databind 2.10.0.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS