CVE-2026-48502
Detail
Description
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.
Metrics
NVD enrichment efforts reference publicly available information to associate
vector strings. CVSS information contributed by other sources is also
displayed.
CVSS 4.0 Severity and Vector Strings:
NVD assessment
not yet provided.
Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CVSS 3.x Severity and Vector Strings:
Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CVSS 2.0 Severity and Vector Strings:
Base
Score:
NVD assessment
not yet provided.
References to Advisories, Solutions, and Tools
By selecting these links, you will be leaving NIST webspace.
We have provided these links to other web sites because they
may have information that would be of interest to you. No
inferences should be drawn on account of other sites being
referenced, or not, from this page. There may be other web
sites that are more appropriate for your purpose. NIST does
not necessarily endorse the views expressed, or concur with
the facts presented on these sites. Further, NIST does not
endorse any commercial products that may be mentioned on
these sites. Please address comments about this page to [email protected].
Weakness Enumeration
| CWE-ID |
CWE Name |
Source |
|
CWE-125
|
Out-of-bounds Read |
GitHub, Inc.
|
|
CWE-190
|
Integer Overflow or Wraparound |
GitHub, Inc.
|
|
CWE-407
|
Inefficient Algorithmic Complexity |
GitHub, Inc.
|
|
CWE-409
|
Improper Handling of Highly Compressed Data (Data Amplification) |
GitHub, Inc.
|
|
CWE-470
|
Use of Externally-Controlled Input to Select Classes or Code ('Unsafe Reflection') |
GitHub, Inc.
|
|
CWE-502
|
Deserialization of Untrusted Data |
GitHub, Inc.
|
|
CWE-674
|
Uncontrolled Recursion |
GitHub, Inc.
|
|
CWE-789
|
Memory Allocation with Excessive Size Value |
GitHub, Inc.
|
|
CWE-1188
|
Insecure Default Initialization of Resource |
GitHub, Inc.
|
Change History
3 change records found show changes
Initial Analysis by NIST
6/23/2026 1:25:05 PM
| Action |
Type |
Old Value |
New Value |
| Added |
CVSS V3.1 |
AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
|
| Added |
CPE Configuration |
OR
*cpe:2.3:a:messagepack:messagepack:*:*:*:*:*:c#:*:* versions up to (excluding) 2.5.301
*cpe:2.3:a:messagepack:messagepack:*:*:*:*:*:c#:*:* versions from (including) 3.0.3 up to (excluding) 3.1.7
|
| Added |
Reference Type |
GitHub, Inc.: https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-382j-8mxh-c7x2 Types: Mitigation, Vendor Advisory
|
CVE Modified by CISA-ADP
6/23/2026 12:16:59 PM
| Action |
Type |
Old Value |
New Value |
| Added |
SSVC |
{"timestamp":"2026-06-23T14:58:22.893152Z","id":"CVE-2026-48502","options":[{"exploitation":"none"},{"automatable":"no"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}
|
New CVE Received from GitHub, Inc.
6/22/2026 6:16:47 PM
| Action |
Type |
Old Value |
New Value |
| Added |
Description |
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.
|
| Added |
CVSS V4.0 |
AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
|
| Added |
CWE |
CWE-125
|
| Added |
CWE |
CWE-190
|
| Added |
CWE |
CWE-407
|
| Added |
CWE |
CWE-409
|
| Added |
CWE |
CWE-470
|
| Added |
CWE |
CWE-502
|
| Added |
CWE |
CWE-674
|
| Added |
CWE |
CWE-789
|
| Added |
CWE |
CWE-1188
|
| Added |
Reference |
https://github.com/MessagePack-CSharp/MessagePack-CSharp/security/advisories/GHSA-382j-8mxh-c7x2
|
| Added |
Affected |
[{"vendor":"MessagePack-CSharp","product":"MessagePack-CSharp","versions":[{"version":">= 3.1.7, < 3.1.7","status":"affected"},{"version":"< 2.5.301","status":"affected"}]}]
|
Quick Info
CVE Dictionary Entry: CVE-2026-48502 NVD
Published Date: 06/22/2026 NVD
Last Modified: 06/23/2026
Source: GitHub, Inc.
|
