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Public proof of conceptFix availableAwaiting NVD analysis

CVE-2026-83557

A public proof of concept exists; no exploitation attested.

  • Published2026-09-01
  • Fixed in2.22.2 · 2.21.6 · 2.18.10
  • WeaknessCWE-502 · CWE-915

Am I affected?

With a domain, we read the version its public headers and pages expose. A distribution build can carry the fix under an older number.

Description

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.

Timeline

dates in UTC
  1. 2026-09-0115:17CVE publishedNVD

Observed activity

isMalicious corpus · updated 2026-11-04 03:37 UTC
Indicators tagged with this CVE, per day0 indicators over 7 days
Block these indicators
  • Firewall list (EDL, text): https://api.ismalicious.com/edl/cve/CVE-2026-83557?format=txt
  • CSV export: https://api.ismalicious.com/edl/cve/CVE-2026-83557?format=csv
  • TAXII collection of exploited CVEs
  • The EDL and CSV take an API key on the Pro plan.

Versions per branch

OSV
jackson-databind
BranchAffectedFixed in
2.22≥ 2.22.0, < 2.22.22.22.2
2.x≥ 2.19.0, < 2.21.62.21.6
2.x≥ 2.11.0, < 2.18.102.18.10
jackson-databind
BranchAffectedFixed in
3.2≥ 3.2.0, < 3.2.23.2.2
3.x≥ 3.0.0, < 3.1.63.1.6

as publishedRanges as NVD and OSV publish them; a distribution’s build can be fixed under an older number.

Products declared by the CNA2 products

As HeroDevs, the CNA that assigned this CVE, declared them in the CVE record; versions as written.

  • FasterXML jackson-databindother versions: not affected

    package com.fasterxml.jackson.core:jackson-databindhttps://repo.maven.apache.org/maven2

    Affected
    • ≥ 2.11.0, < 2.18.10fixed in 2.18.10maven
    • ≥ 2.19.0, < 2.21.6fixed in 2.21.6maven
    • ≥ 2.22.0, < 2.22.2fixed in 2.22.2maven
  • FasterXML jackson-databindother versions: not affected

    package tools.jackson.core:jackson-databindhttps://repo.maven.apache.org/maven2

    Affected
    • ≥ 3.0.0, < 3.1.6fixed in 3.1.6maven
    • ≥ 3.2.0, < 3.2.2fixed in 3.2.2maven

Source: the CNA record (CVE Program), © The MITRE Corporation,CVE Terms of UseCVE recordupdated 2026-09-01

Distribution builds and vendor advisories

Packages from OSV.dev and products from the vendors' CSAF advisories.

version not verifiedVersions not verified: read as OSV.dev and the vendors publish them, not checked against each vendor's release list.

Packages

  • activemqCleanStartall versions · fixed in 6.3.2-r1
  • airbyte-platform-cronChainguardall versions · fixed in 2.0.0-r9and 9 other packages
  • akhqWolfiall versions · fixed in 0.28.0-r11
  • akhqChainguardall versions · fixed in 0.28.0-r11
  • apache-activemq-5.19MinimOSall versions · fixed in 5.19.11-r0and 1 other package
  • apache-activemq-6.3MinimOSall versions · fixed in 6.3.2-r0and 1 other package
  • apache-activemq-fips-6.2Chainguardall versions · fixed in 6.2.10-r1
  • apache-camel-karavan-devmodeChainguardall versions · fixed in 4.18.1-r14

421 more package ranges on OSV.dev

Vendor advisories

  • CVE-2026-83557 Red Hat Product Security2 products fixed · 287 known affected

    com.fasterxml.jackson.core/jackson-databind: tools.jackson.core/jackson-databind: jackson-databind: Path traversal via incomplete type validation

    exploit-intelligence/agent-client-rhel9 as a component of Exploit Intelligence · jenkins-2-plugins.src as a component of OpenShift Developer Tools and Services · jenkins.src as a component of OpenShift Developer Tools and Services · +284 more

  • RHSA-2026:83520 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat build of Quarkus 3.33.4 release and security update

  • RHSA-2026:83082 Red Hat Product Security1 product fixed

    Red Hat Security Advisory: Red Hat build of Quarkus 3.27.6 release and security update

Full record on NVD

Fix

  1. Update jackson-databind to 2.22.2 · 2.21.6 · 2.18.10
  2. Vendor fix Red Hat Product Security RHSA-2026:83520 · 1 productBefore applying this update, make sure all previously released errata relevant to your system have been applied. For details on how to apply this update, refer to: https://access.redhat.com/articles/11258
  3. Vendor fix Red Hat Product Security RHSA-2026:83082 · 1 productBefore applying this update, make sure all previously released errata relevant to your system have been applied. For information about how to apply this update, see https://access.redhat.com/articles/11258.
  4. Workaround from the vendor Red Hat Product Security RHSA-2026:83520 · 1,040 productsIf immediate upgrade is not possible, audit for @JsonTypeInfo properties typed as java.lang.Comparable without a custom PolymorphicTypeValidator. Narrow the type or add a validator that denies java.io.File and similar Comparable implementations. This doesn't apply to global default typing (activate…
  5. No fix available, says the vendor Red Hat Product Security CVE-2026-83557 · 209 productsFix deferred
  6. No fix planned, says the vendor Red Hat Product Security CVE-2026-83557 · 78 productsOut of support scope

Detection

Nuclei template
none so far
ProjectDiscovery
Exploit-DB
no entry
Exploit-DB
Proof-of-concept repositories
none listed
PoC-in-GitHub
Metasploit modules
none listed
Metasploit Framework

Sources

  • NVDCVE recordread 2026-10-23
  • CISA-ADPSSVC decisionpoc2026-09-01
  • OpenCVESSVC decisionpoc—
  • CNACVSS 3.15.6known since 2026-10-23
  • CNAweakness (CWE)CWE-502, CWE-915known since 2026-10-23
  • FIRST EPSSEPSS score0.7 %2026-11-03
  • OSVaffected packages—
  • GitHub AdvisoriesadvisoryMODERATE2026-09-28

Identifiers

Technical details

CVSS v3 Vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L
Published
2026-09-01
Last Modified
2026-09-08
NVD status
Awaiting Analysis
GitHub Advisory
GHSA-gx83-3vf8-gh7j

Frequently asked questions

What is CVE-2026-83557?

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.

Is CVE-2026-83557 actively exploited?

A proof-of-concept exploit exists for CVE-2026-83557, but active exploitation has not been confirmed at this time.

What is the CVSS score for CVE-2026-83557?

CVE-2026-83557 has a CVSS v3 base score of 5.6 (MEDIUM severity), with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L.

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