Medium severity · published Apr 23, 2026
CVE-2026-40894
OpenTelemetry dotnet: Excessive memory allocation when parsing OpenTelemetry propagation headers
5.3
CVSS
0.5%
EPSS
No
On KEV
Description
OpenTelemetry dotnet is a dotnet telemetry framework. In OpenTelemetry.Api 0.5.0-beta.2 to 1.15.2 and OpenTelemetry.Extensions.Propagators 1.3.1 to 1.15.2, The implementation details of the baggage, B3 and Jaeger processing code in the OpenTelemetry.Api and OpenTelemetry.Extensions.Propagators NuGet packages can allocate excessive memory when parsing which could create a potential denial of service (DoS) in the consuming application. This vulnerability is fixed in 1.15.3.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 40% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
OP
OpenTelemetry.Api · open-telemetry
>= 0.5.0-beta.2, < 1.15.3 · source: vendor, NVD
OP
OpenTelemetry.Extensions.Propagators · open-telemetry
>= 1.3.1, < 1.15.3 · source: vendor, NVD
OP
opentelemetry-dotnet · open-telemetry
>= 0.5.0-beta.2, < 1.15.3 · source: vendor
OP
Opentelemetry · Opentelemetry
0.5.0 before 1.15.3 · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-40894
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-40894
Issue Tracking
https://github.com/open-telemetry/opentelemetry-dotnet/pull/1048
Issue Tracking
https://github.com/open-telemetry/opentelemetry-dotnet/pull/3244
Issue Tracking
https://github.com/open-telemetry/opentelemetry-dotnet/pull/3309
Issue Tracking
https://github.com/open-telemetry/opentelemetry-dotnet/pull/533
Issue Tracking
https://github.com/open-telemetry/opentelemetry-dotnet/pull/7061
Mitigation
https://github.com/open-telemetry/opentelemetry-dotnet/security/advisories/GHSA-g94r-2vxg-569j
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