CVE-2026-128085
Received
Received - Intake
OpenTelemetry-Go Attribute Truncation Flaw via U+FFFD
Vulnerability report for CVE-2026-128085, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-11-13
Last updated on: 2026-11-13
Assigner: GitHub, Inc.
Description
Description
OpenTelemetry-Go is the Go implementation of OpenTelemetry. From SDK version 1.33.0, SDK log version 0.9.0, and trace version 1.35.0 until version 1.47.0, the AttributeValueLengthLimit and WithAttributeValueLengthLimit truncation paths in sdk/internal/attrnorm, sdk/log/internal/attrnorm, and trace/auto.go do not count valid U+FFFD replacement characters. This is a distinct incomplete-fix defect in the replacement truncation code introduced by the remediation for CVE-2026-81869. Values composed of or dominated by those characters can therefore exceed the configured character and memory bound in span, log-record, and auto-instrumentation trace attributes. Attacker-controlled telemetry attributes can increase retained memory and pipeline pressure, while confidentiality and integrity are not affected. This issue is fixed in version 1.47.0.
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| opentelemetry | opentelemetry-go | to 1.47.0 (exc) |
| opentelemetry | opentelemetry-go | 1.47.0 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-770 | The product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated. |
| CWE-135 | The product does not correctly calculate the length of strings that can contain wide or multi-byte characters. |
