How severe is CVE-2020-10739?

CVE-2020-10739 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.

Is CVE-2020-10739 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-10739?

CVE-2020-10739 affects Istio. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-10739?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2020-10739 published?

CVE-2020-10739 was published on 2020-06-02 and last updated on 2026-06-17.

CVE-2020-10739

CVE-2020-10739 is a high-severity vulnerability in Istio with a CVSS 3.x base score of 7.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-476.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-476
Affected product: Istio
Published: 2020-06-02
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2020-10739?: 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.
How severe is CVE-2020-10739?: CVE-2020-10739 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2020-10739 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-10739?: CVE-2020-10739 affects Istio. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-10739?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2020-10739 published?: CVE-2020-10739 was published on 2020-06-02 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:istio:istio:*:*:*:*:*:*:*:*

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