CVE-2026-48506CWE-674

MessagePack-CSharp: MessagePackReader.Skip can recurse without enforcing maximum object graph depth

High · published June 22, 2026

CVSS v3.1
7.5
EPSS
0%
Percentile
39.8
In the wild
Unconfirmed
What it is

MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePackReader.TrySkip() recursively descends into nested arrays and maps without incrementing the reader depth or calling the configured depth checks. This bypasses MessagePackSecurity.MaximumObjectGraphDepth, the library's documented protection against deeply nested object graphs. Many generated and dynamic formatters call reader.Skip() when they encounter unknown map keys, unknown array members, ignored fields, or data that should be skipped for forward compatibility. A deeply nested value in one of these skipped positions can therefore cause unbounded recursion and an uncatchable StackOverflowException. This vulnerability is fixed in 2.5.301 and 3.1.7.

The record
Technical detail
CVSS v3.1
7.5 · HIGH
Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS v4.0
Not supplied
EPSS
0.00471 · 39.8th percentile
Weakness
CWE-674 · Uncontrolled Recursion
Published
2026-06-22T21:17Z
EPSS history
Timeline
  • 22 JUN 21:17Z
    MessagePack-CSharp: MessagePackReader.Skip can recurse without enforcing maximum object graph depth
    cvelistv5