CVE-2026-81869

Summary

OpenTelemetry-Go is the Go implementation of OpenTelemetry. From version 1.10.0 until 1.33.0, the sdk/trace/span.go attribute truncation path can fail to enforce AttributeValueLengthLimit for string and string-slice attributes containing the valid Unicode replacement character U+FFFD. safeTruncateValidUTF8 treats the valid replacement rune as invalid UTF-8 and returns the original input, while strings.ToValidUTF8 leaves that valid rune unchanged, so a second safeTruncate attempt can also return the oversized value. An attacker who controls span attribute content can retain values longer than the configured limit, increasing per-span memory use and weakening denial-of-service protection in the instrumented process. This issue is fixed in version 1.33.0.

Affected Software

VendorProductVersion RangeStatus
open-telemetryopentelemetry-go>= 1.10.0, < 1.33.0affected

Weaknesses

  • CWE-176: CWE-176: Improper Handling of Unicode Encoding
  • CWE-400: CWE-400: Uncontrolled Resource Consumption

References