CVE-2026-54513 is a high-severity security vulnerability in com.fasterxml.jackson.core:jackson-databind (maven), affecting versions >= 2.10.0, < 2.18.8. It is fixed in 2.18.8, 2.21.4, 3.1.4.
Summary BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() allowlists any array type based only on clazz.isArray(), without validating the array's component (element) type against the configured allowlist. A PTV built with allowIfSubTypeIsArray() plus an explicit concrete-type allowlist therefore still permits EvilType[] even though EvilType is not allowlisted. When Jackson deserializes the elements and no per-element type IDs are present, it instantiates the component type directly with no further PTV check, bypassing the allowlist. Impact Applications using BasicPolymorphicTypeValidator with allowIfSubTypeIsArray() as a safeguard get no protection for concrete array component types; an attacker controlling JSON can instantiate non-allowlisted types via an array wrapper, re-opening the gadget-instantiation risk PTV is meant to prevent. Affected / Patched (verified via git tag --contains) 2.18 line: >= 2.10.0, < 2.18.8 -> fixed in 2.18.8 2.19-2.21 line: >= 2.19.0, < 2.21.4 -> fixed in 2.21.4 3.x line: >= 3.0.0, < 3.1.4 -> fixed in 3.1.4 PolymorphicTypeValidator was added in 2.10.0 so vulnerability N/A for versions prior to that. Severity / CWE Maintainer: significant. Reporter: HIGH. CWE-184 (Incomplete List of Disallowed Inputs); related CWE-502. Upstream fix FasterXML/jackson-databind#5981; fix PR #5983 (24529da), 2.18 backport PR #5984 (01d1692). Released 2026-06-04 in 2.18.8 / 2.21.4 / 3.1.4. Credits Omkhar Arasaratnam (@omkhar) - finder.
CVE-2026-54513 has a CVSS score of 8.1 (High). 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 (2.18.8, 2.21.4, 3.1.4). Upgrading removes the vulnerable code path.
maven
com.fasterxml.jackson.core:jackson-databind (>= 2.10.0, < 2.18.8)com.fasterxml.jackson.core:jackson-databind (>= 2.19.0, < 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 → 2.18.8 (maven)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-2026-54513 in your environment →Upgrade the following packages to resolve this vulnerability:
com.fasterxml.jackson.core:jackson-databind to 2.18.8 or latercom.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-2026-54513 is a high-severity security vulnerability in com.fasterxml.jackson.core:jackson-databind (maven), affecting versions >= 2.10.0, < 2.18.8. It is fixed in 2.18.8, 2.21.4, 3.1.4.
CVE-2026-54513 has a CVSS score of 8.1 (High). 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 >= 2.10.0, < 2.18.8)tools.jackson.core:jackson-databind (maven) (versions >= 3.0.0, < 3.1.4)Yes. CVE-2026-54513 is fixed in 2.18.8, 2.21.4, 3.1.4. Upgrade to this version or later.
Whether CVE-2026-54513 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 2.18.8 or latercom.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