CVE-2026-42348 json
OpAMP client reads unbounded HTTP response bodies
published 6mo ago modified 14d ago also EUVD-2026-29706 , GHSA-w2jh-77fq-7gp8
- cvss
- 5.9
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.3%
- EPSS 0.3% chance of exploitation in 30 days, percentile 24%
- public exploits
- 0
- none known
Summary
OpenTelemetry.OpAmp.Client is the OpAMP client for OpenTelemetry .NET. Prior to 0.2.0-alpha.1, when receiving responses from the OpAMP server over HTTP, the OpAMP client allocates an unbounded buffer to read all bytes from the server, with no upper-bound on the number of bytes consumed. This could cause memory exhaustion in the consuming application if the configured OpAMP server is attacker-controlled (or a network attacker can MitM the connection) and an extremely large body is returned in the response. This vulnerability is fixed in 0.2.0-alpha.1.
Patch / fix
- nuget OpenTelemetry.OpAmp.Client 0.2.0-alpha.1
- opentelemetry opentelemetry.opamp.client 0.2.0-alpha.1
Is CVE-2026-42348 in your dependencies? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.
Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
- Assessed
- 5mo ago
Exploit prediction
0.31% chance of exploitation in the next 30 days, higher than 24% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| GitHub | 3.1 | 5.9 | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| NVD | 3.1 | 7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| nuget | OpenTelemetry.OpAmp.Client | <0.2.0-alpha.1 |
0.2.0-alpha.1 |
Affected products
- open-telemetry opentelemetry-dotnet-contrib
Classification
- Weakness
-
- CWE-789 Memory Allocation with Excessive Size Value
References
-
github.com
/open-telemetry/opentelemetry-dotnet-contrib/pull/4116
web, issue-tracking
-
github.com
/open-telemetry/opentelemetry-dotnet-contrib/security/advisories/GHSA-w2jh-77fq-7gp8
web, patch, vendor-advisory
-
github.com
/open-telemetry/opentelemetry-dotnet-contrib/commit/bf1fad4fa298ff451cda0efb0ee9c7a7eb46212a
web
-
nvd.nist.gov
/vuln/detail/CVE-2026-42348
advisory
-
github.com
/open-telemetry/opentelemetry-dotnet-contrib
package
Sources
- CVE List CVE-2026-42348
- GitHub Advisory GHSA-w2jh-77fq-7gp8
- NVD CVE-2026-42348
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.
CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.