What is CVE-2019-18817?

CVE-2019-18817 is a high-severity vulnerability in Istio, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2019-11-12.

How severe is CVE-2019-18817?

High severity. CVSS v3 base score is 7.5 out of 10.

Vulnerability in Istio

CVE-2019-18817

Istio 1.3.x before 1.3.5 allows Denial of Service because continue_on_listener_filters_timeout is set to True, a related issue to CVE-2019-18836.

Published 2019-11-12 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.012 (67.4th percentile), scored 2026-10-01.

Low probability of exploitation in the next 30 days, but still tracked. 67th percentile — 67.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.012 · newest: 0.012 · change: 0.000

Affected products

Istio

Weakness classification (CWE)

CWE-835 — Loop with Unreachable Exit Condition (Infinite Loop)

References

istio.io/news/2019/announcing-1.3.5/ (Vendor Advisory)
github.com/istio/istio/issues/18229 (Exploit, Third Party Advisory)

Frequently asked questions

What is CVE-2019-18817?: CVE-2019-18817 is a high-severity vulnerability in Istio, classified under Loop with Unreachable Exit Condition (Infinite Loop). CVSS score: 7.5/10. Published 2019-11-12.
How severe is CVE-2019-18817?: High severity. CVSS v3 base score is 7.5 out of 10.