CVE-2026-90472
Description
A flaw was found in msgpack-java. This vulnerability allows a remote attacker to cause a Denial of Service (DoS) by crafting a malicious payload with deeply nested arrays. The MessageUnpacker.unpackValue() function, responsible for deserializing arrays and maps, lacks proper depth limits, leading to a stack overflow when processing such payloads. This can exhaust the deserializing thread's stack, causing per-request deserialization failures.
Statement
This vulnerability is rated as Moderate impact for Red Hat products because triggering uncontrolled recursion during message parsing causes a thread-level StackOverflowError, resulting in isolated request failure rather than terminating the broader application or virtual machine. Exploitation requires applications to accept and parse untrusted MessagePack data streams directly without prior input validation. The impact is restricted to availability without affecting data confidentiality or system integrity.
Mitigation
No upstream fix is currently released (GitHub issue msgpack/msgpack-java#1015 remains open and PR #1026 is unreleased). As a workaround, applications should validate untrusted MessagePack input and enforce nesting-depth limits when parsing via MessageUnpacker, since the flaw only affects applications that accept and parse untrusted/attacker-supplied MessagePack data streams without nesting-depth limits. The unreleased upstream fix in PR #1026 should be tracked for a future fixed release.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.3 | N/A | 5.3 |
| Attack Vector | Network | N/A | Network |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | None | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | None | N/A | None |
| Integrity Impact | None | N/A | None |
| Availability Impact | Low | N/A | Low |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
cve.org: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
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