OpenTelemetry.Exporter.OneCollector vulnerable to denial of service via unbounded HTTP error response body
OpenTelemetry.Exporter.OneCollector is a .NET exporter that sends telemetry to a OneCollector back-end over HTTP. In versions 1.15.0 and earlier, when a request to the configured back-end or collector results in an unsuccessful HTTP 4xx or 5xx response, the HttpJsonPostTransport class reads the entire response body into memory with no upper bound on the number of bytes consumed in order to include the error response in operator logs. An attacker who controls the configured endpoint, or who can intercept traffic to it via a man-in-the-middle attack, can return an arbitrarily large response body. This causes unbounded heap allocation in the consuming process, leading to high transient memory pressure, garbage-collection stalls, or an OutOfMemoryException that terminates the process. As a workaround, use network-level controls such as firewall rules, mTLS, or a service mesh to prevent man-in-the-middle attacks on the configured back-end or collector endpoint. This issue is fixed in version 1.15.1, which limits the number of bytes read from the response body in an error condition to 4 MiB.
- Published
- May 6, 2026
- Updated
- Jun 17, 2026
- EPSS
- 0.4% · 35th percentile
- CWE
- CWE-770
Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.
Report tools
Action score
23
Monitor
Low priority for now.
- CVSS
- 23 / 40 · 5.9 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.4%
CISA SSVC decision
- Exploitation
- none
- Automatable
- no
- Technical impact
- partial
Vulnrichment: CISA's decision-tree inputs.
CNA vs NVD score
- NVD
- 5.9
- CNA · GitHub_M
- 5.3
- 0.6 point gap
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
| Vendor | Product | CPE |
|---|---|---|
| opentelemetry | opentelemetry.exporter.onecollector | cpe:2.3:a:opentelemetry:opentelemetry.exporter.onecollector |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- opentelemetry opentelemetry.exporter.onecollectorup to 1.15.0 inclusive
Versions reported by the vendor
Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.
open-telemetry opentelemetry-dotnet-contrib
- <= 1.15.0affected
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| NuGet | OpenTelemetry.Exporter.OneCollector | before 1.15.1 | 1.15.1 |
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| open-telemetry opentelemetry-dotnet-contrib | 1.15.1 · description | Vendor (CNA) |
| NuGet:OpenTelemetry.Exporter.OneCollector | 1.15.1 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Anyone who can reach it over the internet can trigger it.
- No account or password is required.
- No user action is required.
- Special conditions such as timing or configuration are required.
If successful
- Confidentiality
- none
- Integrity
- none
- Availability
- high · the service can be disrupted
- Attack vector
- Network
- Attack complexity
- High
- Privileges required
- None
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- None
- Integrity impact
- None
- Availability impact
- High
Weakness class (CWE)
CWE-770 · Allocation of Resources Without Limits or ThrottlingCVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- FloodingCAPEC-125likelihood: High · Medium
- Excessive AllocationCAPEC-130likelihood: Medium · Medium
- XML Ping of the DeathCAPEC-147likelihood: Low · Medium
- Exponential Data ExpansionCAPEC-197likelihood: High · Medium
- Serialized Data Parameter BlowupCAPEC-229likelihood: High · High
- Serialized Data with Nested PayloadsCAPEC-230likelihood: Medium · High
- Oversized Serialized Data PayloadsCAPEC-231likelihood: Medium · High
- HTTP DoSCAPEC-469Low
ATT&CK techniques
- Network Denial of Service:Direct Network FloodT1498.001
- Network Denial of Service:Reflection AmplificationT1498.002
- Endpoint Denial of ServiceT1499
- Endpoint Denial of Service: OS Exhaustion FloodT1499.001
- Endpoint Denial of Service:Service Exhaustion FloodT1499.002
- Endpoint Denial of Service:Application Exhaustion FloodT1499.003
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- github.com/open-telemetry/opentelemetry-dotnet-contrib/pull/4117
- github.com/open-telemetry/opentelemetry-dotnet-contrib/security/advisories/GHSA-55m9-299j-53c7
Vendor advisories and official records. Exploit/PoC links are deliberately left out.