CVE-2026-48515
7.5 · HIGHOverview
CVE-2026-48515 is a high-severity vulnerability affecting messagepack messagepack. It was published on June 22, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
Technical Description
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePack-CSharp's multi-dimensional array formatters read dimension lengths directly from the payload and allocate T[,], T[,,], or T[,,,] before validating that the dimension product matches the encoded element count. The formatter reads a guarded element array header, but allocation of the target multi-dimensional array happens before the dimensions are checked against that element count. A small payload can therefore declare large dimensions, provide an empty or tiny inner array, and cause a large heap allocation before element data is validated. This vulnerability is fixed in 2.5.301 and 3.1.7.
Remediation
Check the references section for vendor advisories and patches from messagepack. Update messagepack to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
Affected Products
| Vendor | Product | Versions | Status |
|---|---|---|---|
| messagepack | messagepack | >= 0, < 2.5.301 | Affected |
Frequently Asked Questions
What is CVE-2026-48515?
CVE-2026-48515 is a high-severity vulnerability affecting messagepack messagepack. It was published on June 22, 2026 and has a CVSS 3.1 base score of 7.5 (HIGH).
How severe is CVE-2026-48515?
This vulnerability has a CVSS 3.1 base score of 7.5, rated HIGH. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.
How do I fix or remediate CVE-2026-48515?
Check the references section for vendor advisories and patches from messagepack. Update messagepack to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2026-48515?
CyberStrike's AI-powered security agents can automatically detect CVE-2026-48515 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.
How CyberStrike Helps
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