CVE.org (no NVD analysis yet)· CNA HeroDevs

CVE-2026-110879: jackson-databind: PolymorphicTypeValidator bypass via generic type arguments and array element types allows arbitrary class instantiation (incomplete fix for CV

Noroxi assessment

Priority: Monitor (action score 39/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.1% (FIRST EPSS); higher than 68.3% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to CISA the attack is automatable: targets can be found by mass scanning.
Fixed version: FasterXML jackson-databind 2.18.12, 2.21.8, 2.22.4.

Low priority for now. Upgrade to FasterXML jackson-databind 2.18.12, 2.21.8, 2.22.4 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

jackson-databind validates the outer class of a class-name type ID but accepts attacker-selected classes inside its generic arguments, even when those classes violate the declared type or would be rejected as direct type IDs. This bypasses the generic-argument validation added for CVE-2026-54512 (GHSA-j3rv-43j4-c7qm), of which this is an incomplete fix. DatabindContext._resolveAndValidateGeneric() checks the outer class against the declared base type and then passes each argument from the type ID to _validateTypeParameter(), which validates the argument against the outer base type rather than enforcing its corresponding declared generic binding. It also invokes validators with arguments that have not passed the subtype check those validators expect. Under the default DefaultBaseTypeLimitingValidator this accepts an unrelated class inside a generic subtype even when the same class is rejected as a direct type ID. Where an allowIfBaseType(...) rule approves the outer type, Jackson substitutes LaissezFaireSubTypeValidator, so the configured validator no longer restricts the embedded arguments. The element type of a plain array type ID such as [Lpkg.Gadget; is likewise left unvalidated once the array's base type is approved. Affected paths include annotation-based class-name polymorphism with a default Jackson 3.x JsonMapper, configured default typing in both Jackson 2.x and 3.x, and integrations that expose that default typing. The default-validator case requires no application-authored validator: with @JsonTypeInfo(use = Id.CLASS), a direct gadget type ID is rejected as "Not a subtype", while a type ID naming a generic wrapper around the same gadget is accepted and deserialized, including attacker-supplied bean properties. Where class-name default typing permits Map, a property declared as Map<String,String> accepts HashMap<FileSystemXmlApplicationContext,String>; map-key discovery then passes the attacker-controlled JSON property name to the selected class's one-string constructor. With Spring on the classpath and attacker-controlled XML the application can load, that constructor loads the XML and invokes ProcessBuilder.start() under the application account, giving arbitrary command execution. This issue affects com.fasterxml.jackson.core:jackson-databind from 2.10.0 and tools.jackson.core:jackson-databind from 3.0.0. Releases before 2.10.0 are not affected, because PolymorphicTypeValidator was introduced in jackson-databind 2.10.0.

CriticalCVSS 9.8 · v3.1—No exploit Fix available

Published: Oct 28, 2026
Updated: Nov 6, 2026
EPSS: 1.1% · 68th percentile
CWE: CWE-502

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 39 / 40 · 9.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.1%

CISA SSVC decision

Exploitation: none
Automatable: yes
Technical impact: total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD: —
CNA · HeroDevs: 9.8; NVD has not scored this yet; the score shown is the CNA’s.

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
A fix has been released

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

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Versions reported by the vendor

Affected version ranges reported by the assigning authority (HeroDevs). Independent of NVD's CPE analysis and usually ahead of it.

FasterXML jackson-databind
- 2.18.12, 2.21.8, 2.22.4, 3.1.8, 3.2.4not affected
- 2.10.0 and later · before 2.18.12affected · maven
- 2.19.0 and later · before 2.21.8affected · maven
- 2.22.0 and later · before 2.22.4affected · maven
- 3.0.0 and later · before 3.1.8affected · maven
- 3.2.0 and later · before 3.2.4affected · maven

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

Ecosystem	Package	Affected range	Fix
Debian:12	jackson-databind	from 0	—
Debian:14	jackson-databind	before 2.22.4-1	2.22.4-1
Maven	com.fasterxml.jackson.core:jackson-databind	from 2.10.0 · before 2.18.8	2.18.8
Maven	com.fasterxml.jackson.core:jackson-databind	from 2.19.0 · before 2.21.4	2.21.4
Maven	com.fasterxml.jackson.core:jackson-databind	from 3.0.0 · before 3.1.4	3.1.4
Maven	tools.jackson.core:jackson-databind	from 3.0.0 · before 3.1.4	3.1.4

Same product

fasterxml: all records

Other highest-scoring records for the same primary product.

CVE-2017-17485FasterXML jackson-databind through 2.8.10 and 2.9.x through 2.9.3 allows unauthenticated remote code execution because of an incomplete fix
54Plan
CVE-2017-7525A deserialization flaw was discovered in the jackson-databind, versions before 2.6.7.1, 2.7.9.1 and 2.8.9, which could allow an unauthentica
50Plan
CVE-2020-8840FasterXML jackson-databind 2.0.0 through 2.9.10.2 lacks certain xbean-reflect/JNDI blocking, as demonstrated by org.apache.xbean.propertyedi
47Plan

Published before and after this one in the same product

← EarlierCVE-2026-68497Sep 11, 2026 · jackson-databind: unbounded numeric parse in Duration and XMLGregorianCalendar deserialization allows CPU denial of service
30Monitor
← EarlierCVE-2026-91776Sep 22, 2026 · jackson-databind: unbounded growth of the type id cache in TypeDeserializerBase retains every unknown raw type ID
30Monitor
← EarlierCVE-2026-91777Sep 22, 2026 · jackson-databind: quadratic forward-reference completion in Collection and Map deserializers
30Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / package	Fixed version	Source
FasterXML jackson-databind	2.18.12	Vendor (CNA)
FasterXML jackson-databind	2.21.8	Vendor (CNA)
FasterXML jackson-databind	2.22.4	Vendor (CNA)
FasterXML jackson-databind	3.1.8	Vendor (CNA)
FasterXML jackson-databind	3.2.4	Vendor (CNA)
debian:jackson-databind	2.22.4-1 · Debian:14	Package registry (OSV)
Maven:com.fasterxml.jackson.core:jackson-databind	2.18.8	Package registry (OSV)
Maven:com.fasterxml.jackson.core:jackson-databind	2.21.4	Package registry (OSV)
Maven:com.fasterxml.jackson.core:jackson-databind	3.1.4	Package registry (OSV)
Maven:tools.jackson.core:jackson-databind	3.1.4	Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

PublishedOct 28, 2026
Fix recordedOct 28, 2026same day
TodayNov 10, 2026+14 d

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

martinfrancoisfinder
AdamKorczreporter
cowtowncoder (Tatu Saloranta)remediation developer

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

CVE-2026-8355757 days apartjackson-databind omits java.lang.Comparable from DefaultBaseTypeLimitingValidator's unsafe base types
22Monitor

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: high · data can be read
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: High
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-502 · Deserialization of Untrusted Data

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

nvd-secondary

Root cause

Data received over the network is deserialized into the language’s native object format without verifying its source. Code paths inside the object can be triggered during deserialization.

The bug in code

The whole CWE-502 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

python

1payload = sock.recv(65536)
2job = pickle.loads(payload)

Fixed

python

1payload = sock.recv(65536)
2if not hmac.compare_digest(sign(payload), header_sig):
3    raise PermissionError("invalid signature")
4job = JobSchema.validate(json.loads(payload))

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

Object InjectionCAPEC-586likelihood: Medium · High

ATT&CK techniques

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Change log

SSVC exploitation— → noneNov 6, 2026, 8:07 PM UTC
Exploit maturity— → noneOct 28, 2026, 2:07 AM UTC
Fix✗ → ✓Oct 28, 2026, 2:07 AM UTC

For records you follow, these changes also arrive as notifications. →

References

github.com/FasterXML/jackson-databind/security/advisories/GHSA-j3rv-43j4-c7qm

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records