CVE-2026-54512
jackson-databind: PolymorphicTypeValidator bypass via generic type parameters allows arbitrary class instantiation
Description
jackson-databind contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor. From 2.10.0 until 2.18.8, 2.21.4, and 3.1.4, jackson-databind's PolymorphicTypeValidator (PTV) is the primary safety mechanism guarding polymorphic deserialization. When polymorphic typing is enabled and a type identifier contains generic parameters (i.e. the type ID string contains <), DatabindContext._resolveAndValidateGeneric() validates only the raw container class name (the substring before <) against the configured PTV. If the container type is approved, the method parses the full canonical type string via TypeFactory.constructFromCanonical() and returns the fully parameterized type without ever validating the nested type arguments against the PTV. The nested type arguments are then resolved, instantiated, and populated as beans during deserialization. An attacker who controls the type ID can therefore place a denied class as a generic type parameter of an allowed container — for example java.util.ArrayList<com.evil.Gadget> when only java.util.ArrayList is allow-listed. The container passes the PTV check; com.evil.Gadget is loaded via Class.forName(name, true, loader), instantiated, and its properties are set from attacker-controlled JSON. This completely bypasses an explicitly configured PTV allow-list. This vulnerability is fixed in 2.18.8, 2.21.4, and 3.1.4.
INFO
Published Date :
June 23, 2026, 9:17 p.m.
Last Modified :
June 27, 2026, 9:01 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | [email protected] |
Solution
- Update jackson-databind to 2.18.8 or later.
- Update jackson-databind to 2.21.4 or later.
- Update jackson-databind to 3.1.4 or later.
Public PoC/Exploit Available at Github
CVE-2026-54512 has a 1 public
PoC/Exploit available at Github.
Go to the Public Exploits tab to see the list.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-54512.
| URL | Resource |
|---|---|
| https://github.com/FasterXML/jackson-databind/commit/434d6c511de7fdd9872f29157aafb6162d12d8d5 | Patch |
| https://github.com/FasterXML/jackson-databind/issues/5988 | Issue Tracking Patch |
| https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-j3rv-43j4-c7qm | Exploit Vendor Advisory |
| https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-j3rv-43j4-c7qm | Exploit Vendor Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-54512 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-54512
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
None
PLpgSQL TypeScript JavaScript HTML CSS Java Dockerfile Go Makefile Shell
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-54512 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-54512 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jun. 27, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:fasterxml:jackson-databind:*:*:*:*:*:*:*:* versions from (including) 2.10.0 up to (excluding) 2.18.8 *cpe:2.3:a:fasterxml:jackson-databind:*:*:*:*:*:*:*:* versions from (including) 2.19.0 up to (excluding) 2.21.4 *cpe:2.3:a:fasterxml:jackson-databind:*:*:*:*:*:*:*:* versions from (including) 3.0.0 up to (excluding) 3.1.4 Added Reference Type GitHub, Inc.: https://github.com/FasterXML/jackson-databind/commit/434d6c511de7fdd9872f29157aafb6162d12d8d5 Types: Patch Added Reference Type GitHub, Inc.: https://github.com/FasterXML/jackson-databind/issues/5988 Types: Issue Tracking, Patch Added Reference Type GitHub, Inc.: https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-j3rv-43j4-c7qm Types: Exploit, Vendor Advisory Added Reference Type CISA-ADP: https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-j3rv-43j4-c7qm Types: Exploit, Vendor Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jun. 24, 2026
Action Type Old Value New Value Added Reference https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-j3rv-43j4-c7qm Added SSVC {'id': 'CVE-2026-54512', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'poc'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-06-24T14:54:06.511108Z'} -
New CVE Received by [email protected]
Jun. 23, 2026
Action Type Old Value New Value Added Affected [{'vendor': 'FasterXML', 'product': 'jackson-databind', 'versions': [{'status': 'affected', 'version': '>= 2.10.0, < 2.18.8'}, {'status': 'affected', 'version': '>= 2.19.0, < 2.21.4'}, {'status': 'affected', 'version': '>= 3.0.0, < 3.1.4'}]}] Added Description jackson-databind contains the general-purpose data-binding functionality and tree-model for Jackson Data Processor. From 2.10.0 until 2.18.8, 2.21.4, and 3.1.4, jackson-databind's PolymorphicTypeValidator (PTV) is the primary safety mechanism guarding polymorphic deserialization. When polymorphic typing is enabled and a type identifier contains generic parameters (i.e. the type ID string contains <), DatabindContext._resolveAndValidateGeneric() validates only the raw container class name (the substring before <) against the configured PTV. If the container type is approved, the method parses the full canonical type string via TypeFactory.constructFromCanonical() and returns the fully parameterized type without ever validating the nested type arguments against the PTV. The nested type arguments are then resolved, instantiated, and populated as beans during deserialization. An attacker who controls the type ID can therefore place a denied class as a generic type parameter of an allowed container — for example java.util.ArrayList<com.evil.Gadget> when only java.util.ArrayList is allow-listed. The container passes the PTV check; com.evil.Gadget is loaded via Class.forName(name, true, loader), instantiated, and its properties are set from attacker-controlled JSON. This completely bypasses an explicitly configured PTV allow-list. This vulnerability is fixed in 2.18.8, 2.21.4, and 3.1.4. Added CVSS V3.1 AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H Added CWE CWE-184 Added CWE CWE-502 Added Reference https://github.com/FasterXML/jackson-databind/commit/434d6c511de7fdd9872f29157aafb6162d12d8d5 Added Reference https://github.com/FasterXML/jackson-databind/issues/5988 Added Reference https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-j3rv-43j4-c7qm