GHSA-9fxm-vc8v-hj55 CVE-2026-54516

jackson-databind's renamed @JsonIgnore'd setters can deserialize via private fields

Medium Maven

Severity: 5.3 / 10; Medium · CVSS 3.1
Exploit chance (EPSS): 0.45%; Chance of exploitation in the next 30 days. Higher than 39.05% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-915 Improperly Controlled Modification of Dynamically-Determined Object Attributes
Fix: Available; 2 packages have a fixed version

Description

Summary

POJOPropertiesCollector._renameProperties() allows a property with @JsonProperty("renamed") on the getter and @JsonIgnore on the setter to be renamed rather than dropped. With MapperFeature.INFER_PROPERTY_MUTATORS enabled (default), the private backing field is retained; during deserialization BeanDeserializerFactory.addBeanProps() sees hasField()==true, builds a FieldProperty, and makes the backing field writable. An attacker supplying the renamed JSON key writes the backing field directly, bypassing the @JsonIgnore on the setter.

Impact

POJOs combining a renamed getter with an ignored setter (a read-only-over-the-wire pattern) have that field silently set from attacker input (property tampering / mass assignment). Not a general gadget; no RCE.

Affected / Patched (verified via `git tag --contains`)

2.21 line: >= 2.21.0, < 2.21.4 -> fixed in 2.21.4 (backport c3d56dd, #5968)
3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4 (#5967, e88cb17)

Severity / CWE

Maintainer: minor. Reporter: HIGH. CWE-915.

Credits

Omkhar Arasaratnam (@omkhar) - finder.

Affected versions

Maven

Package	Vulnerable	Fixed in
com.fasterxml.jackson.core:jackson-databind	`>= 2.21.0, < 2.21.4`	`2.21.4`
com.fasterxml.jackson.core:jackson-databind	`>= 3.0.0, < 3.1.4`	`3.1.4`
tools.jackson.core:jackson-databind	`>= 3.0.0, < 3.1.4`	`3.1.4`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

com.fasterxml.jackson.core:jackson-databind Maven → `2.21.4`

maven

<dependency><groupId>com.fasterxml.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>2.21.4</version></dependency>

gradle

implementation("com.fasterxml.jackson.core:jackson-databind:2.21.4")

tools.jackson.core:jackson-databind Maven → `3.1.4`

maven

<dependency><groupId>tools.jackson.core</groupId><artifactId>jackson-databind</artifactId><version>3.1.4</version></dependency>

gradle

implementation("tools.jackson.core:jackson-databind:3.1.4")

Severity breakdown

CVSS 3.1 5.3

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality: None
Integrity: Low
Availability: None

Weakness

CWE-915: Improperly Controlled Modification of Dynamically-Determined Object Attributes

The product receives input from an upstream component that specifies multiple attributes, properties, or fields that are to be initialized or updated in an object, but it does not properly control which attributes can be modified.

How to prevent it

Implementation: If available, use features of the language or framework that allow specification of allowlists of attributes or fields that are allowed to be modified. If possible, prefer allowlists over denylists. For applications written with Ruby on Rails, use the attr_accessible (allowlist) or attr_protected (denylist) macros in each class that may be used in mass assignment.
Architecture and Design, Implementation: If available, use the signing/sealing features of the programming language to assure that deserialized data has not been tainted. For example, a hash-based message authentication code (HMAC) could be used to ensure that data has not been modified.
Implementation: For any externally-influenced input, check the input against an allowlist of internal object attributes or fields that are allowed to be modified.
Implementation, Architecture and Design: Refactor the code so that object attributes or fields do not need to be dynamically identified, and only expose getter/setter functionality for the intended attributes.

References

Advisories

nvd.nist.gov/vuln/detail/CVE-2026-54516

Packages

github.com/FasterXML/jackson-databind

Timeline

Jun 23, 2026 Published
Oct 25, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-cxp5-3px4-pw24 jackson-databind quadratic forward-reference completion	High	Also affects com.fasterxml.jackson.core:jackson-databind
GHSA-wv8q-qhhj-9h54 jackson-databind retains every unknown raw type ID	High	Also affects com.fasterxml.jackson.core:jackson-databind
GHSA-q4xh-88c3-wmh7 jackson-databind: Duration XMLGregorianCalendar Unbounded Number Parse DoS	High	Also affects com.fasterxml.jackson.core:jackson-databind
GHSA-gx83-3vf8-gh7j jackson-databind: Comparable missing from DefaultBaseTypeLimitingValidator's unsafe base types (incomplete PolymorphicTypeValidator denylist)	Medium	Also affects com.fasterxml.jackson.core:jackson-databind
GHSA-wjgm-6hv5-3cvf jackson-databind: Path Deserialization Missing Scheme Allowlist for FileSystemProvider Resolution	Medium	Also affects com.fasterxml.jackson.core:jackson-databind
GHSA-vvgp-rfg2-7rr6 jackson-databind: Incomplete fix for CVE-2026-54514: eager DNS resolution (SSRF) still present in InetAddress deserialization	Medium	Also affects com.fasterxml.jackson.core:jackson-databind
GHSA-mhm7-754m-9p8w jackson-databind: `@JsonView` bypass for creator properties with `@JsonTypeInfo(include=As.EXTERNAL_PROPERTY)`	Medium	Also affects com.fasterxml.jackson.core:jackson-databind
GHSA-5gvw-p9qm-jgwh jackson-databind: @JsonView bypassed for @JsonUnwrapped container properties on deserialization	Medium	Also affects com.fasterxml.jackson.core:jackson-databind

Is this in your code?

MergeHarbor checks every repository's dependencies against this database, ranks what matters by exploitability and reachability, routes it to the owning team and opens the fix pull request.

Check your repos with MergeHarbor