Summary
jackson-databind has case-insensitive deserialization bypasses per-property @JsonIgnoreProperties
In BeanDeserializerBase.createContextual(), per-property @JsonIgnoreProperties exclusions are applied by _handleByNameInclusion(), producing a contextual deserializer whose BeanPropertyMap has the ignored properties removed. The subsequent per-property case-insensitivity block (triggered by @JsonFormat(ACCEPT_CASE_INSENSITIVE_PROPERTIES)) rebuilds from this._beanProperties (the original, unfiltered map) instead of contextual._beanProperties, then overwrites the filtered map, restoring every property _handleByNameInclusion had just removed. The ignored property becomes writable again.
Affected / Patched
Will be fixed in 2.18.9, 2.21.5, 2.22.1 and 3.1.4.
Severity / CWE
Maintainer: minor. Reporter: Moderate. CWE-915.
Upstream fix
FasterXML/jackson-databind#5962 (PR #5964, 0e1b0b2), milestone 3.1.4. Released 2026-06-04.
Impact
An application that both enables case-insensitive matching and relies on per-property @JsonIgnoreProperties to keep a field unwritable can have that field set from untrusted JSON (mass-assignment-style write).
CVE-2026-54515 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 (3.1.4); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
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.
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. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2026-54515? CVE-2026-54515 is a medium-severity security vulnerability in com.fasterxml.jackson.core:jackson-databind (maven), affecting versions >= 3.1.0, < 3.1.4. It is fixed in 3.1.4.
- How severe is CVE-2026-54515? CVE-2026-54515 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.
- Which packages are affected by CVE-2026-54515?
com.fasterxml.jackson.core:jackson-databind(maven) (versions >= 3.1.0, < 3.1.4)tools.jackson.core:jackson-databind(maven) (versions >= 3.1.0, < 3.1.4)
- Is there a fix for CVE-2026-54515? Yes. CVE-2026-54515 is fixed in 3.1.4. Upgrade to this version or later.
- Is CVE-2026-54515 exploitable, and should I be worried? Whether CVE-2026-54515 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
- What actually determines whether CVE-2026-54515 is exploitable, and how bad it is? 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.
- How do I fix CVE-2026-54515? Upgrade
tools.jackson.core:jackson-databindto 3.1.4 or later.