VulnerabilityPublished 23 Jun 2026

CVE-2026-54515: FasterXML jackson-databind · Mass Assignment

Affects FasterXML jackson-databindSource CVE Database V5

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Not known to be exploited · CVSS 5.3 Medium · fixed in 3.1.4 : update FasterXML jackson-databind when convenient.

Data as of 5 Nov 2026, 23:24 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 3.1.4, 2.21.5, 2.18.9

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

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: Low: Modification of data is possible, but the attacker does not have control over the consequence of a modification, or the amount of modification is limited. The data modification does not have a direct, serious impact on the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Jun 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
Public exploit code: GitHub proofs of concept
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), GitHub proofs of concept, the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade FasterXML jackson-databind to 3.1.4, 2.21.5 or 2.18.9.

Affected software

Product	Affected	Fixed in
FasterXMLjackson-databind	Affected >=3.1.0 <3.1.4	Fixed in 3.1.4
FasterXMLjackson-databind	Affected >=2.19.0 <2.21.5	Fixed in 2.21.5
FasterXMLjackson-databind	Affected >=2.8.0 <2.18.9	Fixed in 2.18.9
Mavencom.fasterxml.jackson.core/jackson-databind`pkg:maven/com.fasterxml.jackson.core/jackson-databind`Other threats	Affected 2.8.0 – 3.1.4 6 affected builds	Fixed in–

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A fix is available in jackson-databind versions 2.18.9, 2.21.5, and 3.1.4. Users should upgrade to one of these versions or later to remediate this vulnerability. Patch status is confirmed by the vendor advisory. No additional mitigation steps are indicated.

Description

jackson-databind contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor. From 2.8.0 until 2.18.9, 2.21.5, and 3.1.4, 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. This vulnerability is fixed in 2.18.9, 2.21.5, and 3.1.4.

Impact

This vulnerability allows properties that should be ignored (and thus not writable) to become writable again, potentially enabling unintended modification of object attributes during deserialization. The CVSS score of 5.3 (medium severity) reflects that the impact is limited to integrity (I:L) without confidentiality or availability impact, and the attack vector is network with low complexity and no privileges or user interaction required.

Summary

CVE-2026-54515 describes a vulnerability in jackson-databind's BeanDeserializerBase.createContextual() method where per-property @JsonIgnoreProperties exclusions are applied correctly initially, removing ignored properties from the BeanPropertyMap. However, when the per-property case-insensitivity feature is enabled via @JsonFormat(ACCEPT_CASE_INSENSITIVE_PROPERTIES), the code rebuilds the property map from the original unfiltered properties, overwriting the filtered map and restoring the ignored properties as writable. This improper control of dynamically-determined object attributes can lead to ignored properties being writable when they should not be. The vulnerability affects jackson-databind versions >=2.8.0 <2.18.9, >=2.18.0 <2.21.5, and >=3.0.0 <3.1.4, and is fixed in versions 2.18.9, 2.21.5, and 3.1.4.

CWE-915Improperly Controlled Modification of Dynamically-Determined Object Attributes (opens in a new tab)
Base weaknessOWASP Top 10 A08:2025: Software or Data Integrity Failures (opens in a new tab)
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.
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.
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 · Input Validation
For any externally-influenced input, check the input against an allowlist of internal object attributes or fields that are allowed to be modified.
OWASP Cheat Sheets
Mass Assignment (opens in a new tab)
Software Supply Chain Security (opens in a new tab)
Infrastructure as Code (opens in a new tab)
OWASP ASVS 4.0.3
V5.1.2 (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

Community reviews

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Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 30 Jun 2026, 23:21 UTC

Public exploits and detectionGitHub proofs of concept

WeaknessesCWE-915

Technical details

References

Community reviews

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