msgpack-java through 0.9.12 Integer Overflow via MAP32 (CVE-2026-90473) | HOL Guard CVE

Unknown severity · Source severity not reportedCVE-2026-90473

msgpack-java through 0.9.12 Integer Overflow via MAP32

Answer in brief

CVE-2026-90473 records a Unknown severity vulnerability in msgpack-java through 0.9.12 Integer Overflow via MAP32. The current sources do not mark it as known exploited. The current feed maps msgpack/msgpack-java (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Sep 12, 2026Updated Sep 12, 2026Source checked Sep 12, 2026First seen by HOL Sep 12, 2026Material review Sep 12, 2026

Upstream Advisory

Key facts

Risk: Unknown severitySource severity not reported
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Not reported

Why this deserves its current priority

A CVSS score is not reported in the current record. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps msgpack/msgpack-java (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
msgpack/msgpack-javageneric	0	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for msgpack/msgpack-java.
Review the reported fix. Monitor this advisory for an available fix and review any installs of the affected package.

Evidence timeline and material changes

Published upstream
Sep 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Sep 12, 2026

Sources and claim methodology

Upstream source description

msgpack-java through 0.9.12 contains an integer overflow vulnerability in MessageUnpacker.skipValue() when processing MAP32 containers with large element counts. Attackers can supply a MAP32 element count at or above 0x40000000 that wraps when doubled, causing the parser cursor to desynchronize and attacker-controlled data to be returned in place of later fields.

Quoted source text, attributed separately from HOL analysis.