CVE-2026-42191

OpenTelemetry.Exporter.OpenTelemetryProtocol is the OTLP (OpenTelemetry Protocol) exporter implementation. From 1.8.0 to 1.15.2, the OTLP disk retry feature in OpenTelemetry.Exporter.OpenTelemetryProtocol silently fell back to Path.GetTempPath() when OTEL_DOTNET_EXPERIMENTAL_OTLP_RETRY=disk was set but OTEL_DOTNET_EXPERIMENTAL_OTLP_DISK_RETRY_DIRECTORY_PATH was not configured. The exporter stored and loaded *.blob files under fixed, signal-named subdirectories (traces, metrics, logs) beneath that shared temporary root path. On multi-user systems where the temporary directory is accessible to other local accounts, this allows an attacker to write crafted *.blob files, read *.blob files written by the application between export failures, or deposit numerous or oversized blob files, degrading retry-loop performance or consuming disk space. This vulnerability is fixed in 1.15.3.

Scoring

Severity
MEDIUM
CVSS base score
6.5
CVSS vector
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:L
EPSS probability
0.11%
CWE
CWE-379
Published
2026-05-12
Last modified
2026-05-13

Affected products

Weakness type

Related vulnerabilities

Markdown version · Browse all CVEs