jackson-databind: unbounded growth of the type id cache in TypeDeserializerBase retains every unknown raw type ID
Priority HIGH 72CWE-400Published · Updated
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 4 fixed, 32 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-400.
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.
Why it matters now
Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00487 42nd percentileScored 2026-11-07
Fix Partial com.fasterxml.jackson.core:jackson-databind (Maven): 2.18.11, 2.21.7, 2.22.3tools.jackson.core:jackson-databind (Maven): 3.1.7, 3.2.3Red Hat: 4 advisoriesRed Hat: 4 fixed, 32 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- Yes
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| FasterXML | jackson-databind | 2.0.0 – 2.18.10; 2.19.0 – 2.21.6; 2.22.0 – 2.22.2 | — | No fix listed | CNA |
| FasterXML | jackson-databind | 3.0.0 – 3.1.6; 3.2.0 – 3.2.2 | — | No fix listed | CNA |
| — | com.fasterxml.jackson.core:jackson-databind (Maven) | 2.0.0 to before 2.18.11 | 2.18.11 | Patch available | GHSA-wv8q-qhhj-9h54 |
| — | com.fasterxml.jackson.core:jackson-databind (Maven) | 2.19.0 to before 2.21.7 | 2.21.7 | Patch available | GHSA-wv8q-qhhj-9h54 |
| — | com.fasterxml.jackson.core:jackson-databind (Maven) | 2.22.0 to before 2.22.3 | 2.22.3 | Patch available | GHSA-wv8q-qhhj-9h54 |
| — | tools.jackson.core:jackson-databind (Maven) | 3.0.0 to before 3.1.7 | 3.1.7 | Patch available | GHSA-wv8q-qhhj-9h54 |
| — | tools.jackson.core:jackson-databind (Maven) | 3.2.0 to before 3.2.3 | 3.2.3 | Patch available | GHSA-wv8q-qhhj-9h54 |
- jackson-databind VendorFasterXML Affected 2.0.0 – 2.18.10; 2.19.0 – 2.21.6; 2.22.0 – 2.22.2 Fixed in — No fix listed CNA
- jackson-databind VendorFasterXML Affected 3.0.0 – 3.1.6; 3.2.0 – 3.2.2 Fixed in — No fix listed CNA
- com.fasterxml.jackson.core:jackson-databind (Maven) Vendor— Affected 2.0.0 to before 2.18.11 Fixed in 2.18.11 Patch available GHSA-wv8q-qhhj-9h54
- com.fasterxml.jackson.core:jackson-databind (Maven) Vendor— Affected 2.19.0 to before 2.21.7 Fixed in 2.21.7 Patch available GHSA-wv8q-qhhj-9h54
- com.fasterxml.jackson.core:jackson-databind (Maven) Vendor— Affected 2.22.0 to before 2.22.3 Fixed in 2.22.3 Patch available GHSA-wv8q-qhhj-9h54
- tools.jackson.core:jackson-databind (Maven) Vendor— Affected 3.0.0 to before 3.1.7 Fixed in 3.1.7 Patch available GHSA-wv8q-qhhj-9h54
- tools.jackson.core:jackson-databind (Maven) Vendor— Affected 3.2.0 to before 3.2.3 Fixed in 3.2.3 Patch available GHSA-wv8q-qhhj-9h54
Remediation
- Fix · GHSA-wv8q-qhhj-9h54 com.fasterxml.jackson.core:jackson-databind (Maven) Fixed in 2.18.11 Advisory →
- Fix · GHSA-wv8q-qhhj-9h54 com.fasterxml.jackson.core:jackson-databind (Maven) Fixed in 2.21.7 Advisory →
- Fix · GHSA-wv8q-qhhj-9h54 com.fasterxml.jackson.core:jackson-databind (Maven) Fixed in 2.22.3 Advisory →
- Fix · GHSA-wv8q-qhhj-9h54 tools.jackson.core:jackson-databind (Maven) Fixed in 3.1.7 Advisory →
- Fix · GHSA-wv8q-qhhj-9h54 tools.jackson.core:jackson-databind (Maven) Fixed in 3.2.3 Advisory →
Red Hat 4 advisories
- RHSA-2026:95762 Released 2026-11-06 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.8 Images Security Update
- Red Hat build of Keycloak 26.6 rhbk/keycloak-operator-bundle, rhbk/keycloak-rhel9, rhbk/keycloak-rhel9-operator
- RHSA-2026:95761 Released 2026-11-06 · Red Hat rating ImportantRed Hat build of Keycloak 26.6.8 Security Update
- Red Hat build of Keycloak 26.6.8
- RHSA-2026:83520 Released 2026-10-15 · Red Hat rating ImportantRed Hat build of Quarkus 3.33.4 release and security update
- Red Hat build of Quarkus 3.33.4.redhat at.yawk.lz4.lz4-java-1.11.1.rhel8-redhat-00001.jar, com.fasterxml.jackson.core.jackson-core-2.21.7.redhat-00001.jar, com.fasterxml.jackson.core.jackson-databind-2.21.7.redhat-00001.jar +10
Show 1 more Red Hat advisories
- RHSA-2026:83082 Released 2026-10-15 · Red Hat rating ImportantRed Hat build of Quarkus 3.27.6 release and security update
- Red Hat build of Quarkus 3.27.6.redhat at.yawk.lz4.lz4-java-1.11.1.rhel8-redhat-00001.jar, com.fasterxml.jackson.core.jackson-core-2.21.7.redhat-00001.jar, com.fasterxml.jackson.core.jackson-databind-2.21.7.redhat-00001.jar +11
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Exploit Intelligence | Affected | — |
| OpenShift Developer Tools and Services | Affected | — |
| OpenShift Serverless | Affected | — |
| Red Hat AI Inference Server | Affected | — |
| Red Hat AMQ Broker 7 | Affected | — |
| Red Hat Ansible Automation Platform 2 | Affected | — |
| Red Hat Build of Keycloak | Affected | — |
| Red Hat Ceph Storage 8 | Affected | — |
| Red Hat Ceph Storage 9 | Affected | — |
| Red Hat Certificate System 10 | Affected | — |
| Red Hat Certificate System 11 | Affected | — |
| Red Hat Data Grid 8 | Affected | — |
| Red Hat Enterprise Linux 10 | Affected | — |
| Red Hat Enterprise Linux 8 | Affected | — |
| Red Hat Enterprise Linux 9 | Affected | — |
| Red Hat Enterprise Linux AI (RHEL AI) 3 | Affected | — |
| Red Hat Fuse 7 | Affected | — |
| Red Hat JBoss Enterprise Application Platform 7 | Affected | — |
| Red Hat JBoss Enterprise Application Platform 8 | Affected | — |
| Red Hat JBoss Enterprise Application Platform Expansion Pack | Affected | — |
| Red Hat JBoss Web Server 7 | Affected | — |
| Red Hat Lightspeed for Runtimes Operator | Affected | — |
| Red Hat Offline Knowledge Portal | Affected | — |
| Red Hat OpenShift AI (RHOAI) | Affected | — |
| Red Hat OpenShift Dev Spaces | Affected | — |
| Red Hat Satellite 6 | Affected | — |
| Red Hat Single Sign-On 7 | Affected | — |
| Red Hat build of Apache Camel - HawtIO 4 | Affected | — |
| Red Hat build of Apache Camel 4 for Quarkus 3 | Affected | — |
| Red Hat build of Apache Camel for Spring Boot 4 | Affected | — |
| Red Hat build of Apicurio Registry 3 | Affected | — |
| Red Hat build of Debezium 3 | Affected | — |
| Red Hat build of Keycloak 26.6 | Fixed | RHSA-2026:95762 |
| Red Hat build of Keycloak 26.6.8 | Fixed | RHSA-2026:95761 |
| Red Hat build of Quarkus 3.27.6.redhat | Fixed | RHSA-2026:83082 |
| Red Hat build of Quarkus 3.33.4.redhat | Fixed | RHSA-2026:83520 |
Not affected: 3 products
- Red Hat Hardened Images
- Red Hat build of Quarkus 3.27.6.redhat
- Red Hat build of Quarkus 3.33.4.redhat
Timeline
- 2026-10-02 Threatist record created from CVE-2026-91776
- 2026-10-03 Alias added: GHSA-wv8q-qhhj-9h54
- 2026-10-06 Affected versions changed · Red Hat
- 2026-10-16 Fix available: RHSA-2026:83520 · Red Hat
- 2026-10-16 Fix available: RHSA-2026:83082 · Red Hat
- 2026-10-16 Fix available: Red Hat build of Quarkus 3.27.6.redhat, Red Hat build of Quarkus 3.33.4.redhat · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95761 · Red Hat
- 2026-11-06 Fix available: Red Hat build of Keycloak 26.6.8 · Red Hat
- 2026-11-06 Fix available: RHSA-2026:95762 · Red Hat
- 2026-11-06 Fix available: Red Hat build of Keycloak 26.6 · Red Hat
References
Other 7
- https://github.com/FasterXML/jackson-databind/commit/2870d1d6dc1b7e1c07ee11dd5b04ab71cddbb577
- https://github.com/FasterXML/jackson-databind
- https://github.com/FasterXML/jackson-databind/releases/tag/jackson-databind-2.18.11
- https://github.com/FasterXML/jackson-databind/releases/tag/jackson-databind-2.21.7
- https://github.com/FasterXML/jackson-databind/releases/tag/jackson-databind-2.22.3
- https://github.com/FasterXML/jackson-databind/releases/tag/jackson-databind-3.1.7
- https://github.com/FasterXML/jackson-databind/releases/tag/jackson-databind-3.2.3
More FasterXML vulnerabilities
- TI-2017-12774 FasterXML jackson-databind through 2.8.10 and 2.9.x through 2.9.3 allows unauthenticated… CVSS 3.1CRITICAL 9.8
- TI-2026-48269 Resource allocation without limits in FasterXML jackson-core CVSS 4.0HIGH 8.7
- TI-2017-05167 Deserialization of untrusted data in FasterXML jackson-databind CVSS 3.1CRITICAL 9.8
- TI-2026-61988 jackson-databind: quadratic forward-reference completion in Collection and Map deserializers CVSS 3.1HIGH 7.5
- TI-2026-60476 Uncontrolled resource consumption in FasterXML jackson-core CVSS 3.1HIGH 7.5
- TI-2026-60468 jackson-core: quadratic backtracking in NumberInput.PATTERN_FLOAT via looksLikeValidNumber() enables ReDoS CVSS 3.1HIGH 7.5
Sources
- CVE-2026-91776 · CVE Program
- CVE-2026-91776 · NVD
- FIRST EPSS
- GHSA-wv8q-qhhj-9h54 · GitHub Advisory Database · CC BY 4.0
- CVE-2026-91776 · Red Hat security data · CC BY 4.0
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