CVE-2026-48502 (GCVE-0-2026-48502)
Vulnerability from cvelistv5 – Published: 2026-06-22 21:18 – Updated: 2026-06-23 15:05
VLAI
Title
MessagePack-CSharp: Denial of service vulnerabilities can swamp the CPU or crash the process with stack and heap overflows
Summary
MessagePack for C# is a MessagePack serializer for C#. Prior to 2.5.301 and 3.1.7, MessagePackReader.ReadDateTime() can allocate stack memory based on an attacker-controlled MessagePack extension length. In the slow path for timestamp extension parsing, the computed tokenSize includes the extension body length from the wire and is used in a stackalloc operation before the extension length is validated as one of the valid timestamp sizes. A very small payload can claim a large timestamp extension body and cause a stack allocation large enough to trigger an uncatchable StackOverflowException, terminating the host process. This vulnerability is fixed in 2.5.301 and 3.1.7.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: partial
CISA Coordinator (v2.0.3)
CWE
- CWE-125 - Out-of-bounds Read
- CWE-190 - Integer Overflow or Wraparound
- CWE-407 - Inefficient Algorithmic Complexity
- CWE-409 - Improper Handling of Highly Compressed Data (Data Amplification)
- CWE-470 - Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection')
- CWE-502 - Deserialization of Untrusted Data
- CWE-674 - Uncontrolled Recursion
- CWE-789 - Memory Allocation with Excessive Size Value
- CWE-1188 - Insecure Default Initialization of Resource
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://github.com/MessagePack-CSharp/MessagePack… | x_refsource_CONFIRM |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| MessagePack-CSharp | MessagePack-CSharp |
Affected:
>= 3.1.7, < 3.1.7
Affected: < 2.5.301 |
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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