How severe is CVE-2020-8843?

CVE-2020-8843 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.

Is CVE-2020-8843 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-8843?

CVE-2020-8843 affects Istio. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-8843?

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-2020-8843 published?

CVE-2020-8843 was published on 2020-02-14 and last updated on 2026-06-17.

CVE-2020-8843

CVE-2020-8843 is a high-severity vulnerability in Istio with a CVSS 3.x base score of 7.4. 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-20.

Key facts

Severity: High (CVSS 3.x base score 7.4)
CVSS v2: 5.8
EPSS exploit prediction: 1% (61st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Istio
Published: 2020-02-14
Last modified: 2026-06-17

Description

An issue was discovered in Istio 1.3 through 1.3.6. Under certain circumstances, it is possible to bypass a specifically configured Mixer policy. Istio-proxy accepts the x-istio-attributes header at ingress that can be used to affect policy decisions when Mixer policy selectively applies to a source equal to ingress. To exploit this vulnerability, someone has to encode a source.uid in this header. This feature is disabled by default in Istio 1.3 and 1.4.

Frequently asked questions

What is CVE-2020-8843?: An issue was discovered in Istio 1.3 through 1.3.6. Under certain circumstances, it is possible to bypass a specifically configured Mixer policy. Istio-proxy accepts the x-istio-attributes header at ingress that can be used to affect policy decisions when Mixer policy selectively applies to a source equal to ingress. To exploit this vulnerability, someone has to encode a source.uid in this header. This feature is disabled by default in Istio 1.3 and 1.4.
How severe is CVE-2020-8843?: CVE-2020-8843 has a CVSS 3.x base score of 7.4, rated high severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability none.
Is CVE-2020-8843 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (61st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-8843?: CVE-2020-8843 affects Istio. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-8843?: 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-2020-8843 published?: CVE-2020-8843 was published on 2020-02-14 and last updated on 2026-06-17.

References

Affected products (1)

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

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