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CriticalVulnerabilityCVE-2026-110879updated 28 Oct 2026, 01:18 UTC

Jackson JSON library can be tricked into loading dangerous classes

A widely used Java library that reads JSON data can be fooled into creating objects of classes it should refuse. An attacker who can send crafted data to the application may be able to run commands on the server.

Official source
SeverityCriticalCVSS 9.8 of 10
Being exploited?UnclearNo reports either way yet
Fix available?UnclearNo fixed version published in the sources yet
How sure is this?Official sourceBacked by an official source

How the attack works simplified

  1. 1Attacker sends JSONCrafted type ID names a generic wrapper
  2. 2Jackson accepts typeGeneric arguments are not validated
  3. 3Gadget class createdMap key triggers one-string constructor
  4. 4XML loadedSpring loads attacker-controlled XML
  5. 5Command runsProcessBuilder.start() under app account
  6. ResultAttacker runs commands on the server

What happened

jackson-databind does not validate classes nested inside generic type arguments, so an attacker-chosen gadget class is accepted and deserialized. This is an incomplete fix for CVE-2026-54512 (GHSA-j3rv-43j4-c7qm).

Why it is dangerous: Successful exploitation can lead to arbitrary command execution under the application's account, which means full compromise of the affected service. Any Java service accepting untrusted JSON with class-name polymorphic typing is at risk.

Are you affected?

You are affected if you use com.fasterxml.jackson.core:jackson-databind 2.10.0 or later, or tools.jackson.core:jackson-databind 3.0.0 or later, with class-name polymorphism (for example @JsonTypeInfo(use = Id.CLASS)) or default typing enabled, and Spring is on the classpath.

com.fasterxml.jackson.core:jackson-databind from 2.10.0; tools.jackson.core:jackson-databind from 3.0.0. Versions before 2.10.0 are not affected.

What to do

  1. Check whether your project uses jackson-databind 2.10.0+ or 3.0.0+ with class-name polymorphism or default typing enabled
  2. Update jackson-databind to a patched release as soon as one is published by the Jackson project
  3. Until patched, disable class-name default typing and avoid Id.CLASS on untrusted input
  4. Restrict deserialization of untrusted data to explicit, known types

Timeline

  1. 28 Oct 2026, 01:16 UTC
    Publicly disclosed
  2. 28 Oct 2026, 01:16 UTC
    Reported by NVD · NVD
  3. 28 Oct 2026, 01:18 UTC
    Picked up by Zero Radar

Sources 1 report, oldest first

Official vendor, government CERT or advisory database

Technical details

ID
CVE-2026-110879
CVSS
9.8 / 10
EPSS
1.2% chance of exploitation within 30 days
Disclosed
28 Oct 2026, 01:16 UTC
On Zero Radar
28 Oct 2026, 01:18 UTC (1 min after disclosure)
Last change
28 Oct 2026, 01:18 UTC

The plain-language parts and the attack diagram were written by an AI model (anthropic/claude-haiku-5.5) from the sources above. Facts like versions, exploitation and dates come from the sources themselves. How Zero Radar works

Jackson JSON library can be tricked into loading dangerous classes · Zero Radar