High severity · published Jun 23, 2026
CVE-2026-54513
jackson-databind: Array subtype allowlist bypass in BasicPolymorphicTypeValidator (allowIfSubTypeIsArray)
8.1
CVSS
1.2%
EPSS
No
On KEV
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, BasicPolymorphicTypeValidator.Builder.allowIfSubTypeIsArray() allowlists any array type based only on clazz.isArray(), without validating the array's component (element) type against the configured allowlist. A PTV built with allowIfSubTypeIsArray() plus an explicit concrete-type allowlist therefore still permits EvilType[] even though EvilType is not allowlisted. When Jackson deserializes the elements and no per-element type IDs are present, it instantiates the component type directly with no further PTV check, bypassing the allowlist. This vulnerability is fixed in 2.18.8, 2.21.4, and 3.1.4.
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
High
Privileges
None
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.2% · higher than 69% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
JA
jackson-databind · FasterXML
>= 2.10.0, < 2.18.8; >= 2.19.0, < 2.21.4; >= 3.0.0, < 3.1.4 · source: vendor, NVD
C4
Cryostat 4 on RHEL 9 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat AMQ Clients · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Certificate System 10.8 for RHEL-8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10.0 Extended Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 8.8 Telecommunications Update Service · Red Hat
All versions, or not specified · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-54513
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-54513
Patch
https://github.com/FasterXML/jackson-databind/commit/01d1692c8d0ed03e51a0e3c4f8a9e6908e4931e5
Patch
https://github.com/FasterXML/jackson-databind/commit/24529da29fdf46ff94ca38de9ebf31cd188f5e8e
Issue Tracking
https://github.com/FasterXML/jackson-databind/issues/5981
Issue Tracking
https://github.com/FasterXML/jackson-databind/issues/5983
Issue Tracking
https://github.com/FasterXML/jackson-databind/pull/5984
Patch
https://github.com/FasterXML/jackson-databind/security/advisories/GHSA-rmj7-2vxq-3g9f
More from jackson-databind
10.0
CVE-2018-14721
FasterXML jackson-databind 2.x before 2.9.7 might allow remote attackers to conduct server-side request forgery (SSRF) attacks by leveraging failure to block the axis2-jaxws class…
9.8
CVE-2026-110879
jackson-databind: PolymorphicTypeValidator bypass via generic type arguments and array element types allows arbitrary class instantiation (incomplete fix for CVE-2026-54512)
9.8
CVE-2019-14893
A flaw was discovered in FasterXML jackson-databind in all versions before 2.9.10 and 2.10.0, where it would permit polymorphic deserialization of malicious objects using the…
9.8
CVE-2019-14892
A flaw was discovered in jackson-databind in versions before 2.9.10, 2.8.11.5 and 2.6.7.3, where it would permit polymorphic deserialization of a malicious object using…
9.8
CVE-2020-9546
FasterXML jackson-databind 2.x before 2.9.10.4 mishandles the interaction between serialization gadgets and typing, related to…