CVE-2026-45676: OpenTelemetry eBPF Instrumentation ELF Parser Denial of Service

Technical summary

CVE-2026-45676 is a memory safety vulnerability in OpenTelemetry eBPF Instrumentation's ELF parser. The parser fails to validate section offsets, counts, and string table offsets from untrusted ELF binaries, leading to out-of-bounds pointer dereferences or buffer over-reads. When the agent attempts to determine process language by analyzing an executable, a crafted ELF with malicious metadata can cause the parser to dereference invalid pointers or slice beyond string table boundaries, triggering a panic condition. The root causes align with CWE-20 (improper input validation) and CWE-248 (uncaught exception), indicating both insufficient validation and inadequate error handling.

Business impact

This vulnerability enables denial-of-service attacks against OpenTelemetry eBPF Instrumentation deployments. An attacker with local system access can crash the instrumentation agent by introducing a malformed executable, temporarily eliminating application observability. For organizations relying on eBPF-based monitoring for performance troubleshooting, security analytics, or SLA compliance, agent crashes degrade visibility into application behavior and may delay incident response. The impact is localized to the instrumentation agent itself—no code execution, confidentiality, or integrity compromise—but repeated crashes could strain operational teams and mask legitimate issues during attack windows.

Affected systems

OpenTelemetry eBPF Instrumentation versions prior to 0.9.0 are vulnerable. The vulnerability requires local code execution or file system access to introduce a crafted ELF binary into an environment where the agent is actively monitoring processes. Systems running the instrumentation agent in containerized, multi-tenant, or shared-compute environments face elevated exposure if non-privileged users can place executables on the filesystem.

Exploitability

Exploitation requires local access (AV:L) and low privilege (PR:L), with no user interaction needed (UI:N). An attacker must be able to write a file to a location where the instrumentation agent will attempt to parse it. While the barrier to entry is moderate—requiring existing local access—the mechanics are straightforward: place a malformed ELF, trigger the agent to analyze it, and observe the crash. The attack is deterministic and reliable, though the practical window depends on agent restart policies and monitoring scope.

Remediation

Upgrade OpenTelemetry eBPF Instrumentation to version 0.9.0 or later. The patched version includes hardened ELF parsing logic that validates section metadata before dereferencing pointers and implements proper bounds checking on string table access. Verify the upgrade against the official OpenTelemetry project advisories to confirm the specific version deployed in your environment.

Patch guidance

Apply version 0.9.0 or any subsequent release. Follow your organization's standard change management process for instrumentation agent updates, including testing in a staging environment to confirm compatibility with your observability stack. Rolling restarts of instrumentation agents are typically sufficient; no database migrations or configuration changes are required. Confirm patch application by checking agent version logs or querying the instrumentation API endpoint if available.

Detection guidance

Monitor logs from OpenTelemetry eBPF Instrumentation agents for panic or unhandled exception messages, particularly those referencing ELF parsing, section offsets, or string table operations. Correlate agent crashes with suspicious file creation or execution activity on the host, especially files with unusual ELF headers or metadata. Organizations using container security or file integrity monitoring can flag attempts to place or modify ELF binaries in monitored directories.

Why prioritize this

Although CVSS 5.5 (MEDIUM) reflects limited scope and no data breach risk, this vulnerability merits prompt attention because it directly undermines observability infrastructure. Disrupting monitoring visibility creates a tactical advantage for attackers conducting lateral movement or persistence activities. For environments where instrumentation is critical to security monitoring or compliance, even brief outages compound downstream incident response risk. Prioritize patching systems in high-value environments first.

Risk score, explained

The CVSS 3.1 score of 5.5 reflects Attack Vector Local (AV:L), Attack Complexity Low (AC:L), Privileges Required Low (PR:L), User Interaction None (UI:N), and high Availability impact (A:H). This scoring appropriately penalizes the local requirement and low-privilege barrier, but acknowledges the certainty and severity of denial-of-service outcome. The score does not account for the strategic value of disabling observability, which may warrant elevated internal risk ratings in security-critical deployments.

Frequently asked questions