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Fencer Vulns
high 7.5

CVE-2026-91776 json

jackson-databind: unbounded growth of the type id cache in TypeDeserializerBase retains every unknown raw type ID

published 2026-09-23 47 d ago modified 2026-09-30 40 d ago also EUVD-2026-85002 , GHSA-wv8q-qhhj-9h54

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.5%
EPSS 0.5% chance of exploitation in 30 days, percentile 42%
public exploits
0
none known

Summary

TypeDeserializerBase._findDeserializer() in FasterXML jackson-databind caches the resolved deserializer under the raw, attacker-supplied type ID. When name-based polymorphism is configured with a fallback, for example @JsonTypeInfo(use = Id.NAME, defaultImpl = ...), every distinct unrecognized type ID resolves to the same fallback deserializer but is retained as its own key in the _deserializers map. That map has no configurable bound and lives for the lifetime of the type deserializer, so an attacker who can repeatedly supply fresh unknown type IDs causes monotonic memory retention across requests. The reporter observed 10,000 retained entries from 10,000 distinct unknown IDs, against a single entry for a control that repeated one unknown ID the same number of times, isolating attacker-controlled key cardinality from request volume. Exploitation requires an application that enables name-based polymorphism with a defaultImpl or equivalent fallback, accepts attacker-influenced type IDs, and reuses a long-lived ObjectMapper across requests. The fix stops caching fallback resolutions for unrecognized IDs and bounds both the number of cached entries and the length of a cacheable type ID.

Patch / fix

  • maven com.fasterxml.jackson.core:jackson-databind 2.18.11, 2.21.7, 2.22.3
  • maven tools.jackson.core:jackson-databind 3.1.7, 3.2.3
  • com.fasterxml.jackson.core jackson-databind 2.18.11, 2.21.7, 2.22.3
  • tools.jackson.core jackson-databind 3.1.7, 3.2.3
  • jackson-databind Debian 14 2.18.11-1

debian advisories DEBIAN-CVE-2026-91776

  • jackson-databind SLES for SAP applications 16.0, SLES 16.0 2.18.11-160000.1.1
  • jackson-core SLES for SAP applications 16.0, SLES 16.0 2.18.11-160000.1.1
  • jackson-annotations SLES for SAP applications 16.0, SLES 16.0 2.18.11-160000.1.1
  • jackson-core SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.18.11-150200.3.30.1
  • jackson-databind SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.18.11-150200.3.36.1
  • jackson-annotations SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.18.11-150200.3.28.1
  • jackson-dataformat-xml SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.18.11-150200.5.8.1
  • jackson-dataformats-binary SLES for SAP 15 SP6, SLES for SAP 15 SP5, SLES for SAP 15 SP4 +8 more 2.18.11-150200.3.29.1

suse advisories SUSE-SU-2026:24149-1SUSE-SU-2026:4394-1

  • jackson-databind openSUSE Leap 16.0 2.18.11-160000.1.1
  • jackson-core openSUSE Leap 16.0 2.18.11-160000.1.1
  • jackson-annotations openSUSE Leap 16.0 2.18.11-160000.1.1
  • jackson-databind openSUSE Tumbleweed 2.18.11-1.1

opensuse advisories openSUSE-SU-2026:22034-1openSUSE-SU-2026:11877-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-91776 updated cvss 7.5

jackson-databind: com.fasterxml.jackson/jackson-core: jackson-databind: Denial of Service via unbounded cache growth in TypeDeserializerBase

  • Red Hat Exploit Intelligence exploit-intelligence/agent-client-rhel9 Red Hat OpenShift Developer Tools and Services jenkins, jenkins-2-plugins, ocp-tools-4/jenkins-rhel8, ocp-tools-4/jenkins-rhel9 Red Hat OpenShift Serverless openshift-serverless-1/kn-ekb-receiver-rhel9, openshift-serverless-1/kn-ekb-dispatcher-rhel9, openshift-serverless-1/kn-eventing-integrations-log-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-s3-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sns-sink-rhel9, openshift-serverless-1/kn-eventing-integrations-aws-sqs-sink-rhel9, +4 more Red Hat AI Inference Server rhaii/vllm-gaudi-rhel9, rhaiis/vllm-cuda-rhel9 Red Hat AMQ Broker 7 jackson-databind Red Hat Ansible Automation Platform 2 python-drools-jpy-jar, python3x-drools-jpy-jar, python3.11-drools-jpy-jar, python3.12-drools-jpy-jar, ansible-automation-platform-24/de-minimal-rhel8, ansible-automation-platform-24/de-minimal-rhel9, +5 more
    +26 more products
    Red Hat build of Apache Camel - HawtIO 4 jackson-databind Red Hat build of Apache Camel 4 for Quarkus 3 jackson-databind Red Hat build of Apache Camel for Spring Boot 4 jackson-databind Red Hat build of Apicurio Registry 3 jackson-databind Red Hat build of Debezium 3 jackson-databind Red Hat Build of Keycloak jackson-databind Red Hat Ceph Storage 8 liborc1 Red Hat Ceph Storage 9 liborc, liborc2, libarrow, parquet-libs Red Hat Certificate System 10 redhat-pki Red Hat Certificate System 11 redhat-pki Red Hat Data Grid 8 jackson-databind Red Hat Enterprise Linux 8 jss, pki-ca, idm-jss, ldapjdk, pki-kra, pki-acme, +25 more Red Hat Enterprise Linux 9 pki-ca, pki-kra, pki-acme, pki-base, pki-core, pki-tools, +16 more Red Hat Enterprise Linux 10 dogtag-pki, assertj-core Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-gaudi-rhel9 Red Hat Fuse 7 jackson-databind Red Hat JBoss Enterprise Application Platform 7 jackson-databind, jboss-eap-7/eap74-els-openjdk8-openshift-rhel8, jboss-eap-7/eap74-els-openjdk11-openshift-rhel8, jboss-eap-7/eap74-els-openjdk17-openshift-rhel8 Red Hat JBoss Enterprise Application Platform 8 jackson-databind Red Hat JBoss Enterprise Application Platform Expansion Pack jackson-databind Red Hat JBoss Web Server 7 jboss-webserver-7/jws70-openjdk17-openshift-rhel9, jboss-webserver-7/jws70-openjdk21-openshift-rhel9 Red Hat Lightspeed for Runtimes Operator rh-lightspeed-runtimes/runtimes-agent-init-rhel9 Red Hat Offline Knowledge Portal offline-knowledge-portal/rhokp-rhel9 Red Hat OpenShift AI (RHOAI) rhoai/odh-modelmesh-rhel9, rhoai/odh-vllm-gaudi-rhel9, rhoai/odh-spark-operator-rhel9, rhoai/odh-trustyai-service-rhel9, rhoai/odh-th-torch-cpu-py312-rhel9, rhoai/odh-th-torch-cuda-py312-rhel9, +18 more Red Hat OpenShift Dev Spaces devspaces/server-rhel9, devspaces/openvsx-rhel9, devspaces/pluginregistry-rhel9, devspaces/multicluster-redirector-rhel9 Red Hat Satellite 6 candlepin, puppetserver, openvox-server, candlepin-selinux Red Hat Single Sign-On 7 jackson-databind
    under investigation
  • Red Hat build of Keycloak 26.6 rhbk/keycloak-rhel9 26.6-24, rhbk/keycloak-rhel9-operator 26.6-24, rhbk/keycloak-operator-bundle 26.6.8-2
    fixed: vendor fix RHSA-2026:95762
  • Red Hat build of Keycloak 26.6.8
    fixed: vendor fix RHSA-2026:95761
  • Red Hat build of Quarkus 3.27.6.redhat jackson-databind 2.21.7.redhat-00001
    fixed: vendor fix RHSA-2026:83082
  • Red Hat build of Quarkus 3.33.4.redhat jackson-databind 2.21.7.redhat-00001
    fixed: vendor fix RHSA-2026:83520
  • Red Hat build of Quarkus 3.27.6.redhat jna 5.8.0, db2 1.21.4, h2 2.3.230, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, +1009 more Red Hat build of Quarkus 3.33.4.redhat jna 5.8.0, h2 2.4.240, y18n 5.0.8, cliui 8.0.1, guice 5.1.0, wasm 2.15.3, +1016 more
    not affected: vulnerable code not present
  • Red Hat Hardened Images maven3.9
    not affected: component not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
Proof of concept is public
Automatable
yes
Technical impact
partial
Assessed
47 d ago

Exploit prediction

0.49% chance of exploitation in the next 30 days, higher than 42% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-wv8q-qhhj-9h54 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven com.fasterxml.jackson.core:jackson-databind
>=2.0.0, <2.18.11
>=2.19.0, <2.21.7
>=2.22.0, <2.22.3
2.18.11
2.21.7
2.22.3
maven tools.jackson.core:jackson-databind
>=3.0.0, <3.1.7
>=3.2.0, <3.2.3
3.1.7
3.2.3

Affected products

  • FasterXML jackson-databind

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.