Answer in brief
CVE-2026-83557 records a Medium severity (CVSS 5.6) vulnerability in jackson-databind omits java.lang.Comparable from DefaultBaseTypeLimitingValidator's unsafe base types. The current sources do not mark it as known exploited. The current feed maps FasterXML/jackson-databind (generic), FasterXML/jackson-databind (generic), com.fasterxml.jackson.core:jackson-databind (maven), com.fasterxml.jackson.core:jackson-databind (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.6. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps FasterXML/jackson-databind (generic), FasterXML/jackson-databind (generic), com.fasterxml.jackson.core:jackson-databind (maven), com.fasterxml.jackson.core:jackson-databind (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| FasterXML/jackson-databindgeneric | >=2.11.0 <2.18.10 || >=2.19.0 <2.21.6 || >=2.22.0 <2.22.2 | 2.18.10, 2.21.6, 2.22.2 |
| FasterXML/jackson-databindgeneric | >=3.0.0 <3.1.6 || >=3.2.0 <3.2.2 | 3.1.6, 3.2.2 |
| com.fasterxml.jackson.core:jackson-databindmaven | >=2.11.0,<2.18.10 | 2.18.10 |
| com.fasterxml.jackson.core:jackson-databindmaven | >=2.19.0,<2.21.6 | 2.21.6 |
| com.fasterxml.jackson.core:jackson-databindmaven | >=2.22.0,<2.22.2 | 2.22.2 |
| com.fasterxml.jackson.core:jackson-databindmaven | >=2.11.0 <2.18.10 | 2.18.10 |
| com.fasterxml.jackson.core:jackson-databindmaven | >=2.19.0 <2.21.6 | 2.21.6 |
| com.fasterxml.jackson.core:jackson-databindmaven | >=2.22.0 <2.22.2 | 2.22.2 |
| tools.jackson.core:jackson-databindmaven | >=3.0.0,<3.1.6 | 3.1.6 |
| tools.jackson.core:jackson-databindmaven | >=3.2.0,<3.2.2 | 3.2.2 |
| tools.jackson.core:jackson-databindmaven | >=3.0.0 <3.1.6 | 3.1.6 |
| tools.jackson.core:jackson-databindmaven | >=3.2.0 <3.2.2 | 3.2.2 |
Published upstream
Sep 1, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 28, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 1, 2026
DefaultBaseTypeLimitingValidator is the PolymorphicTypeValidator applied automatically whenever @JsonTypeInfo is used without an explicitly configured custom validator. It denies polymorphic resolution only for a fixed set of "unsafe base types", and its isSafeSubType method returns true unconditionally for every base type outside that set. java.lang.Comparable was absent from the list despite being implemented by a very large fraction of JDK and application classes, comparable in breadth to java.io.Serializable, which is on the list for that reason. An application declaring an @JsonTypeInfo-annotated property or class with Comparable as its base type, and no custom PolymorphicTypeValidator, will accept a type identifier for essentially any class implementing Comparable. This yields an attacker-controlled object instantiation primitive; a demonstrated case constructs a java.io.File for an arbitrary attacker-chosen path, which becomes path-traversal-adjacent if the application subsequently calls path-sensitive methods on the value. No class implementing Comparable has been identified that yields code execution through deserialization alone. Global Default Typing via activateDefaultTyping is not affected, because that method structurally requires an explicit PolymorphicTypeValidator argument. This affects com.fasterxml.jackson.core:jackson-databind from 2.11.0 before 2.18.10, from 2.19.0 before 2.21.6, and from 2.22.0 before 2.22.2, and tools.jackson.core:jackson-databind from 3.0.0 before 3.1.6 and from 3.2.0 before 3.2.2. Users should upgrade to 2.18.10, 2.21.6, 2.22.2, 3.1.6, or 3.2.2.
Quoted source text, attributed separately from HOL analysis.