CVE-2026-54516 is a medium-severity security vulnerability in com.fasterxml.jackson.core:jackson-databind (maven), affecting versions >= 2.21.0, < 2.21.4. It is fixed in 2.21.4, 3.1.4.
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.INFERPROPERTY_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.
CVE-2026-54516 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment.
A fixed version is available (2.21.4, 3.1.4). Upgrading removes the vulnerable code path.
maven
com.fasterxml.jackson.core:jackson-databind (>= 2.21.0, < 2.21.4)com.fasterxml.jackson.core:jackson-databind (>= 3.0.0, < 3.1.4)tools.jackson.core:jackson-databind (>= 3.0.0, < 3.1.4)com.fasterxml.jackson.core:jackson-databind → 2.21.4 (maven)com.fasterxml.jackson.core:jackson-databind → 3.1.4 (maven)tools.jackson.core:jackson-databind → 3.1.4 (maven)Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
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Already deployed Kodem? See CVE-2026-54516 in your environment →Upgrade the following packages to resolve this vulnerability:
com.fasterxml.jackson.core:jackson-databind to 2.21.4 or latercom.fasterxml.jackson.core:jackson-databind to 3.1.4 or latertools.jackson.core:jackson-databind to 3.1.4 or laterKodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
CVE-2026-54516 is a medium-severity security vulnerability in com.fasterxml.jackson.core:jackson-databind (maven), affecting versions >= 2.21.0, < 2.21.4. It is fixed in 2.21.4, 3.1.4.
CVE-2026-54516 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
com.fasterxml.jackson.core:jackson-databind (maven) (versions >= 2.21.0, < 2.21.4)tools.jackson.core:jackson-databind (maven) (versions >= 3.0.0, < 3.1.4)Yes. CVE-2026-54516 is fixed in 2.21.4, 3.1.4. Upgrade to this version or later.
Whether CVE-2026-54516 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
com.fasterxml.jackson.core:jackson-databind to 2.21.4 or latercom.fasterxml.jackson.core:jackson-databind to 3.1.4 or latertools.jackson.core:jackson-databind to 3.1.4 or later