CVE-2026-68494

A flaw was found in jackson-core. A remote attacker can exploit an incomplete fix in the non-blocking JSON parser by streaming specially crafted JSON data in small chunks. This bypasses the intended number length constraint, causing the parser to accumulate excessive memory per connection. This uncontrolled memory growth can lead to a denial of service (DoS) by exhausting the Java Virtual Machine (JVM) heap.

This is an Important denial of service vulnerability in jackson-core's asynchronous JSON parser. A remote, unauthenticated attacker can exploit an incomplete fix to bypass number length constraints, leading to unbounded memory accumulation and potential JVM heap exhaustion in reactive frameworks processing chunked JSON input.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Upgrade com.fasterxml.jackson.core:jackson-core to a fixed version, such as 2.18.8 or later, 2.21.4 or later, or the first fixed release in the applicable 2.22.x stream. For Jackson 3.x, upgrade to 3.1.4 or later, or the first fixed release in the applicable 3.2.x stream. If upgrading is not immediately possible, do not expose the non-blocking parser to untrusted, incrementally streamed JSON. Where feasible, use a synchronous parser or buffer and enforce strict request-size, connection-timeout, and concurrency limits at the ingress layer. Apply the upgrade as soon as possible because ingress limits reduce exposure but do not correct the parser defect.