Medium severity · published Apr 23, 2026
CVE-2026-40891
OpenTelemetry dotnet: Unbounded `grpc-status-details-bin` parsing in OTLP/gRPC retry handling
5.3
CVSS
0.2%
EPSS
No
On KEV
Description
OpenTelemetry dotnet is a dotnet telemetry framework. From 1.13.1 to before 1.15.2, When exporting telemetry over gRPC using the OpenTelemetry Protocol (OTLP), the exporter may parse a server-provided grpc-status-details-bin trailer during retry handling. Prior to the fix, a malformed trailer could encode an extremely large length-delimited protobuf field which was used directly for allocation, allowing excessive memory allocation and potential denial of service (DoS). This vulnerability is fixed in 1.15.2.
CVSS vector
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Adjacent
Complexity
High
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 9% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
opentelemetry-dotnet · open-telemetry
>= 1.13.1, < 1.15.3 · source: vendor
OP
Opentelemetry · Opentelemetry
1.13.1 before 1.15.3 · source: NVD
Affected product
OP
opentelemetry-dotnet
open-telemetry
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