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Critical

Apache Fory fory-core Java SDK replace-resolve deserialization checks bypass

IdentifiersCVE-2026-50076CWE-502· Deserialization of Untrusted Data

CVE-2026-50076 is a deserialization of untrusted data vulnerability in the Java replace-resolve path of Apache Fory fory-core on Java/JVM platforms. It affects org.apache.fory:fory-core versions before 1.1.0. By supplying crafted Fory serialized data, a remote attacker can bypass multiple intended deserialization safeguards, specifically class registration enforcement, TypeChecker validation, and DisallowedList checks. Successful exploitation can cause invocation of classpath-present readResolve and readExternal hooks during deserialization, creating a dangerous execution path in applications that deserialize untrusted external data using the affected library.

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ANALYST BRIEF

Impact, mitigation & remediation

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Impact

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Successful exploitation allows a remote attacker to defeat Apache Fory’s deserialization safety controls and reach classpath-available readResolve/readExternal hooks. This can expose backend systems to unauthorized code execution or other attacker-controlled logic execution depending on the classes available on the target classpath. The provided CVSS v3.1 vector (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N) indicates network-reachable exploitation with no privileges or user interaction required, and high confidentiality and integrity impact.

Mitigation

If you can’t patch tonight, do this now.

If immediate upgrade is not possible, reduce exposure by preventing applications from deserializing untrusted or externally supplied Fory serialized data, especially across network-facing endpoints. Restrict or disable affected deserialization paths where feasible and review deployments for reachable services using the vulnerable fory-core library. However, the provided advisory does not describe a complete workaround; upgrading to 1.1.0 or later is the primary mitigation.

Remediation

Patch, then assume compromise.

Upgrade Apache Fory fory-core Java SDK to version 1.1.0 or later. Apache states that version 1.1.0 fixes this issue, including stricter verification/sanitization in the affected deserialization path. Organizations should also audit dependency trees and identify applications or endpoints that accept untrusted Fory-serialized input.
PUBLIC EXPLOITS

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