Istio 1.4.x before 1.4.9 and Istio 1.5.x before 1.5.4 contain the following vulnerability when telemetry v2 is enabled: by sending a specially crafted packet, an attacker could trigger a Null Pointer Exception resulting in a Denial of Service. This could be sent to the ingress gateway or a sidecar, triggering a null pointer exception which results in a denial of service. This also affects servicemesh-proxy where a null pointer exception flaw was found in servicemesh-proxy. When running Telemetry v2 (not on by default in version 1.4.x), an attacker could send a specially crafted packet to the ingress gateway or proxy sidecar, triggering a denial of service.
Conclusion & alert: CVE-2020-10739 is rated Moderate Risk (60.2/100): CVSS High severity, with medium exploitation likelihood (EPSS 2.33%). Core evidence: EPSS rose +1.72% over the last day, indicating growing attacker interest. Mandatory action: Review affected assets and schedule remediation.
Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.
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 | 0.61% | 2.33% | +1.72% |
| 2 | 2025-06-04 | 0.50% | 0.61% | +0.12% |
| 3 | 2025-03-30 | — | 0.50% | — |
Full EPSS history (13 records total)
CVSS metrics for this CVE.
| Base score | Version | Severity | Vector | Exploitability | Impact | Score source |
|---|---|---|---|---|---|---|
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 7.5 | 3.1 | HIGH |
|
3.9 | 3.6 | [email protected] |
| 5.0 | 2.0 | MEDIUM |
|
10.0 | 2.9 | [email protected] |
| vendor | priority | summary | link |
|---|---|---|---|
redhat
|
high | — | https://access.redhat.com/security/cve/CVE-2020-10739 |
| URL | Tags |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2020-10739 | Broken Link Issue Tracking Third Party Advisory |
| https://github.com/istio/envoy/commit/8788a3cf255b647fd14e6b5e2585abaaedb28153#diff-fcf2cf5dd389b5285f882ba4a8708633 | Patch Third Party Advisory |
| https://istio.io/news/security/istio-security-2020-005/ | Mitigation Vendor Advisory |