MediumCVE-2026-83557

    FasterXML Jackson-databind: Deserialization of Untrusted Data (CVE-2026-83557)

    Published Last modified Sources: Red Hat, BSI, OSV, Hersteller, CVE.org, SUSE

    What is affected, what to do

    A flaw was found in jackson-databind. This vulnerability allows a remote attacker to control object creation by exploiting an incomplete list of restricted types in the DefaultBaseTypeLimitingValidator.

    Update FasterXML Jackson-databind to version 2.18.10, FasterXML Jackson-databind to version 2.21.6, FasterXML Jackson-databind to version 2.22.2.

    Affected
    • FasterXML Jackson-databind lt 2.11.0..2.18.10
    • FasterXML Jackson-databind lt 2.19.0..2.21.6
    • FasterXML Jackson-databind lt 2.22.0..2.22.2
    • FasterXML Jackson-databind lt 3.0.0..3.1.6
    • FasterXML Jackson-databind lt 3.2.0..3.2.2
    Fixed in
    • FasterXML Jackson-databind 2.18.10
    • FasterXML Jackson-databind 2.21.6
    • FasterXML Jackson-databind 2.22.2
    • FasterXML Jackson-databind 3.1.6
    • FasterXML Jackson-databind 3.2.2

    Not sure whether and how you are affected? Ask a question about this vulnerability

    Metrics

    5.6

    Priority

    XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.

    Source: Vendor (CNA), CVSS v3

    5.6

    CVSS v3

    Severity Medium on the scale from 0 to 10.

    Source: Red Hat, BSI, OSV, Hersteller, CVE.org, SUSE

    0.7 %

    EPSS score

    Low — model estimates < 1% exploitation likelihood.

    Source: FIRST EPSS, percentile 53.8

    Show all metrics
    Severity
    Medium
    Priority (0–325)

    The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?

    Read in glossary
    76.04 Methodology
    Exploit maturity

    An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.

    Read in glossary
    no public PoC known
    XIEM Effective CVSS

    XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.

    Read in glossary
    5.6 Methodology
    CVSS v3

    CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.

    Read in glossary
    5.6
    EPSS score

    The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.

    Read in glossary
    0.7 %
    Low — model estimates < 1% exploitation likelihood.
    EPSS percentile

    The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.

    Read in glossary
    53.8
    High — this CVE ranks above the median of all CVEs scored today (rank ≥ 36%).
    KEV status

    The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.

    Read in glossary
    —
    Published
    CISA assessment (SSVC)
    Exploitation: proof of concept · not automatable · Technical impact: partial
    Source: CISA Vulnrichment, as of 1 September 2026
    CWE

    CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.

    Read in glossary
    CWE-502, CWE-915

    Detection rules

    No NEOSEC detection rule is available for this vulnerability yet.

    Classification under NIS2 and CRA

    Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.

    NIS2

    NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.

    Read in glossary
    Handle the vulnerability in regular vulnerability handling under Art. 21(2)(e) NIS2.
    CRA

    The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.

    Read in glossary
    From 11.12.2027, Annex I Part II CRA requires manufacturers of affected products with digital elements to handle vulnerabilities without delay and provide security updates.
    ISO/IEC 27001

    ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.

    Read in glossary
    Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.

    Description

    A flaw was found in jackson-databind. This vulnerability allows a remote attacker to control object creation by exploiting an incomplete list of restricted types in the DefaultBaseTypeLimitingValidator. By crafting malicious input, an attacker can cause the application to create arbitrary file objects, potentially leading to path traversal if these objects are then used in sensitive operations.

    Source: redhat_csaf, BSI WID Portal, BSI CSAF, OSV (Open Source Vulnerabilities), GitHub Security Advisories, NVD (NIST), cvelistv5, suse_csaf

    Affected products

    The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.

    Affected products
    Affected versionsFixed in
    FasterXMLjackson-databind
    • 3.2.0 – < 3.2.2
    • 2.19.0 – < 2.21.6
    • 2.11.0 – < 2.18.10
    • 3.0.0 – < 3.1.6
    • 2.22.0 – < 2.22.2
    • 3.2.2
    • 2.21.6
    • 2.18.10
    • 3.1.6
    • 2.22.2
    FasterXMLJackson Databind
    • < 2.22.2
    • < 2.18.10
    • < 3.2.2
    • < 2.21.6
    • < 3.1.6
    • 2.22.2
    • 2.18.10
    • 3.2.2
    • 2.21.6
    • 3.1.6
    IBMQRadar SIEM
    • < 7.6.0.3
    • <7.5.0 UP16 IF01
    • 7.6.0.3
    • —
    mavencom.fasterxml.jackson.core:jackson-databind
    • 2.12.5
    • 2.12.0-rc1
    • 2.17.2
    • 2.14.3
    • 2.18.6
    • 2.19.2
    • 2.19.1
    • 2.21.5
    • 2.12.6
    • 2.15.4
    • 2.15.3
    • 2.15.2
    • 2.14.1
    • 2.18.0
    • 2.18.4
    • 2.13.0
    • 2.18.7
    • 2.18.0-rc1
    • 2.13.0-rc2
    • 2.12.7
    • 2.18.3
    • 2.13.5
    • 2.20.0-rc1
    • 2.13.4
    • 2.16.0
    • 2.19.3
    • 2.16.0-rc1
    • 2.20.1
    • 2.12.1
    • 2.17.0
    • 2.12.2
    • 2.12.7.2
    • 2.11.0
    • 2.13.3
    • 2.12.7.1
    • 2.15.0-rc1
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    Vendors and products

    Weakness classes (CWE)

    • CWE-502Deserialization of Untrusted Data

      Base

      The product deserializes untrusted data without sufficiently ensuring that the resulting data will be valid.

      Entry at MITRE CWE-502

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

      Base

      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.

      Entry at MITRE CWE-915

    References & sources

    • github.comGHSA-gx83-3vf8-gh7jThird-party advisory
    • github.comFasterXML/jackson-databind#6155Patch, Issue tracking
    • github.comFasterXML/jackson-databind#6156Issue tracking
    • github.comFix commit (2.x line, forward-merged to 2.21, 2.22 and the 3.x branches)Patch
    • NVD (NIST)vuln/detail/CVE-2026-83557advisory
    • github.comFasterXML/jackson-databindpackage
    • github.comFasterXML/jackson-databind/releases/tag/jackson-databind-2.18.10web
    • github.comFasterXML/jackson-databind/releases/tag/jackson-databind-2.21.6web
    • github.comFasterXML/jackson-databind/releases/tag/jackson-databind-2.22.2web
    • github.comFasterXML/jackson-databind/releases/tag/jackson-databind-3.1.6web
    • github.comFasterXML/jackson-databind/releases/tag/jackson-databind-3.2.2web

    Changes to this CVE

    Who changed this CVE and when: NVD (analysis, affected products, CVSS), the CVE publisher (CNA) and additional providers such as CISA (ADP).

    1. Received36c7be3b…

      CVSS V3.1: AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

      Weakness type: CWE-502, CWE-915

      Description added or changed

      Show 9 original changes
      Individual changes of this event as published by NVD
      TypeActionBeforeAfter
      Descriptionadded
      —
      DefaultBaseTypeLimitingValidator is the PolymorphicTypeValidator applied automatically whenever @JsonTypeInfo is used without an explicitly configured custom validator. It denies polymorphic resolution only for a fixed set of "unsafe base types", and its isSafeSubType method returns true unconditionally for every base type outside that set. java.lang.Comparable was absent from the list despite being implemented by a very large fraction of JDK and application classes, comparable in breadth to java.io.Serializable, which is on the list for that reason. An application declaring an @JsonTypeInfo-annotated property or class with Comparable as its base type, and no custom PolymorphicTypeValidator, will accept a type identifier for essentially any class implementing Comparable. This yields an attacker-controlled object instantiation primitive; a demonstrated case constructs a java.io.File for an arbitrary attacker-chosen path, which becomes path-traversal-adjacent if the application subsequently calls path-sensitive methods on the value. No class implementing Comparable has been identified that yields code execution through deserialization alone. Global Default Typing via activateDefaultTyping is not affected, because that method structurally requires an explicit PolymorphicTypeValidator argument. This affects com.fasterxml.jackson.core:jackson-databind from 2.11.0 before 2.18.10, from 2.19.0 before 2.21.6, and from 2.22.0 before 2.22.2, and tools.jackson.core:jackson-databind from 3.0.0 before 3.1.6 and from 3.2.0 before 3.2.2. Users should upgrade to 2.18.10, 2.21.6, 2.22.2, 3.1.6, or 3.2.2.
      CVSSadded
      —
      AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
      Weakness type (CWE)added
      —
      CWE-502
      Weakness type (CWE)added
      —
      CWE-915
      Affected versions (publisher)added
      —
      New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/83xxx/CVE-2026-83557.json">CVE-2026-83557</a>
      Referenceadded
      —
      https://github.com/FasterXML/jackson-databind/commit/eb3b7fc0f9c0d27f471550ac3316b17d1987388f
      Referenceadded
      —
      https://github.com/FasterXML/jackson-databind/issues/6156
      Referenceadded
      —
      https://github.com/FasterXML/jackson-databind/pull/6155
      Referenceadded
      —
      https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-gx83-3vf8-gh7j

      Source identifier: 36c7be3b-2937-45df-85ea-ca7133ea542c

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