What is CVE-2023-45612?

CVE-2023-45612 is a high-severity vulnerability in Jetbrains Ktor, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 8.6/10. Published 2023-10-09.

How severe is CVE-2023-45612?

High severity. CVSS v3 base score is 8.6 out of 10.

Is CVE-2023-45612 known to be exploited?

10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

XXE in Jetbrains Ktor

CVE-2023-45612

In JetBrains Ktor before 2.3.5 default configuration of ContentNegotiation with XML format was vulnerable to XXE

Vulnerability class: XXE (XML External Entity)

Published 2023-10-09 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:N/A:N.

EPSS exploit prediction

EPSS: 0.007 (52.7th percentile), scored 2026-10-20.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 53rd percentile — 52.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.006 · newest: 0.007 · change: +0.001

Affected products

Jetbrains Ktor — versions 0

Weakness classification (CWE)

CWE-611 — Improper Restriction of XML External Entity Reference (XXE)

Public proof-of-concept exploits

References

www.jetbrains.com/privacy-security/issues-fixed/ (Patch, Vendor Advisory)

Frequently asked questions

What is CVE-2023-45612?: CVE-2023-45612 is a high-severity vulnerability in Jetbrains Ktor, classified under Improper Restriction of XML External Entity Reference (XXE). CVSS score: 8.6/10. Published 2023-10-09.
How severe is CVE-2023-45612?: High severity. CVSS v3 base score is 8.6 out of 10.
Is CVE-2023-45612 known to be exploited?: 10 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.