CVE-2026-90473 Details
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.
A vulnerability allowing integer overflow has been identified in msgpack-java versions through 0.9.12. The issue arises in the MessageUnpacker.skipValue() method when handling MAP32 containers with large element counts. Attackers can exploit this by supplying a MAP32 element count of 0x40000000 or higher, which, when doubled, wraps around and causes the parser's cursor to become desynchronized. This desynchronization leads to the unintentional return of attacker-controlled data in place of subsequent fields. The vulnerability is present in the 'msgpack-core' component, specifically within the 'org.msgpack.core.MessageUnpacker' class.
The vulnerability can be remediated by using overflow-safe arithmetic when handling MAP32 and ARRAY32 lengths. Apply the same fix to the ARRAY32 branch in the MessageUnpacker class.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 12, 2026CISA-ADP
Assessed Sep 21, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://github.com/msgpack/msgpack-java | [email protected] | ProductSource CodeVendor |
| https://github.com/msgpack/msgpack-java/blob/v0.9.12/msgpack-core/src/main/java/org/msgpack/core/MessageUnpacker.java#L573-L581 | [email protected] | Source CodeVendor |
| https://github.com/msgpack/msgpack-java/issues/1014 | [email protected] | Issue TrackingTechnical DescriptionVendor |
| https://www.vulncheck.com/advisories/msgpack-java-through-0.9.12-integer-overflow-via-map32 | [email protected] | AdvisoryVendor |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-190 | Integer Overflow or Wraparound | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| msgpack-java | <= 0.9.12 (semver) |
CPE
Remediation
| |
Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 21, 2026 | CVE Modified | CISA-ADP |
| Sep 12, 2026 | New CVE Received | [email protected] |