CVE-2026-41310 | OpenTelemetry .NET Zipkin exporter has unbounded remote endpoint cache leading to memory growth

OpenTelemetry.Exporter.Zipkin is the .NET Zipkin exporter for OpenTelemetry. In versions 1.15.2 and earlier, the Zipkin exporter remote endpoint cache accepts unbounded key growth derived from span attributes. In high-cardinality scenarios, a process using Zipkin export for client or producer spans could experience avoidable memory growth under sustained unique remote endpoint values, increasing process memory usage over time and degrading availability. This issue is fixed in version 1.15.3, which introduces a bounded, thread-safe LRU cache for remote endpoints with a fixed maximum size.

Published: 2026-05-06 Last update: 2026-05-11 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-41310 is rated Low Risk (29.4/100): CVSS Medium severity, with low exploitation likelihood (EPSS 0.31%). Mandatory action: Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-41310

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.02% 0.31% +0.29%
2 2026-05-22 0.05% 0.02% -0.03%
3 2026-05-12 0.05%

Full EPSS history (4 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-41310

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
5.3 3.1 MEDIUM
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:L)
Might cause slowdowns, glitches, or partial disruption—not a full brick.
3.9 1.4 [email protected]

Weakness enumeration for CVE-2026-41310

GitHub Security Advisory for CVE-2026-41310

GHSA-88hf-wf7h-7w4m · Severity: medium · Ecosystem: nuget — OpenTelemetry's Zipkin remote endpoint cache could grow without bounds and increase memory pressure

Affected software / configurations for CVE-2026-41310

Vendor Product Version Raw CPE
opentelemetry opentelemetry.exporter.zipkin < 1.15.3 cpe:2.3:a:opentelemetry:opentelemetry.exporter.zipkin:*:*:*:*:*:.net:*:*

References for CVE-2026-41310

cvelogic Threat Intelligence