CVE-2026-10722: Integer Overflow in Cilium eBPF BTF Loading – Patch Guidance

Technical summary

CVE-2026-10722 is an integer overflow vulnerability in the loadRawSpec function within cilium/ebpf's btf/btf.go file. The vulnerability occurs during eBPF collection specification loading (LoadCollectionSpec/LoadCollectionSpecFromReader) when offset arguments are manipulated. The integer overflow leads to incorrect buffer boundary calculations in BTF parsing, potentially causing memory access violations. The vulnerability is assigned CWE-189 (Numeric Errors) and CWE-190 (Integer Overflow), reflecting the root cause. Attack surface is limited to local processes with permissions to invoke the affected functions.

Business impact

This vulnerability primarily affects availability of systems running vulnerable Cilium eBPF versions. In containerized and Kubernetes environments where Cilium provides networking and security services, an availability impact could disrupt pod-to-pod communication or observability features. Organizations relying on eBPF-based application instrumentation or network policies should prioritize patching to prevent service degradation. The low CVSS score reflects the local-only attack vector and limited scope, but the functional dependency of Cilium in modern cloud infrastructure elevates practical risk.

Affected systems

Cilium eBPF versions up to and including 0.21.0 are vulnerable. Any application or service embedding or depending on this library is affected if deployed with vulnerable versions. This includes Cilium CNI plugin deployments, eBPF-based observability tools, and custom applications using Cilium eBPF for kernel instrumentation. Container runtimes, orchestration platforms, and security tools using Cilium for networking or monitoring should audit their dependency versions.

Exploitability

The vulnerability requires local system access and appropriate privileges to invoke the affected LoadCollectionSpec/LoadCollectionSpecFromReader functions, placing it in the 'low' exploitability category per the CVSS score. However, public disclosure of the vulnerability increases the likelihood of proof-of-concept code or weaponized tools becoming available. In multi-tenant container environments or systems with weak privilege boundaries, the local-only restriction may not provide strong protection. The attack requires no user interaction, making it straightforward to automate once exploitation methods are publicly demonstrated.

Remediation

Apply the patch identified by commit hash 533dfc82fd228bfadf42ea7180c39de7d9af47fa to Cilium eBPF. Verify against the official Cilium GitHub repository and release notes to confirm patched versions. Organizations should upgrade Cilium eBPF beyond version 0.21.0 and rebuild or redeploy any applications or container images that embed the library. For Kubernetes clusters using Cilium CNI, update the Cilium Helm chart or manifests to pull patched container images.

Patch guidance

Identify all systems and applications using Cilium eBPF by reviewing dependency manifests (go.mod files), container image layers, and runtime dependencies. Prioritize patching development and test environments first to validate compatibility. For production Cilium CNI deployments, coordinate patching with change management to minimize network service disruption. Verify that patched versions are available in your software supply chain (container registries, package managers) before scheduling updates. Test eBPF program loading and execution in staging to confirm the patch resolves the issue without regression.

Detection guidance

Monitor system logs and kernel audit trails for failed eBPF program loads or BTF parsing errors that correlate with unexpected process termination or resource exhaustion. Application performance monitoring tools may flag sudden increases in memory access violations or segmentation faults in processes using Cilium eBPF. Check running process and container image versions against known-vulnerable Cilium eBPF versions using Software Bill of Materials (SBOM) scanning. Network telemetry gaps or unexpected CNI plugin restarts in Kubernetes environments may indicate exploitation attempts.

Why prioritize this

While the CVSS score is low and attack vector is local-only, several factors justify near-term action: public disclosure accelerates exploitation development, widespread Cilium deployment in containerized environments increases organizational exposure, and availability impact on networking infrastructure can cascade across dependent services. Organizations with relaxed privilege separation or multi-tenant container clusters face elevated practical risk. Patching is straightforward and carries minimal regression risk, making this a high-value remediation effort relative to effort required.

Risk score, explained

The CVSS 3.1 score of 3.3 (LOW) reflects the confluence of local-only attack vector (AV:L), low attack complexity (AC:L), and low privilege requirements (PR:L), balanced against limited scope (S:U) and impact confined to availability denial (A:L) with no confidentiality or integrity impact. The score is mathematically justified but does not fully capture organizational risk in cloud-native environments where Cilium is foundational infrastructure. Security teams should supplement the base score with contextual risk assessment based on deployment architecture and privilege model.

Frequently asked questions