What is CVE-2025-29904?

CVE-2025-29904 is a medium-severity vulnerability in Jetbrains Ktor, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 5.3/10. Published 2025-03-12.

How severe is CVE-2025-29904?

Medium severity. CVSS v3 base score is 5.3 out of 10.

Is CVE-2025-29904 known to be exploited?

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

Vulnerability in Jetbrains Ktor

CVE-2025-29904

In JetBrains Ktor before 3.1.1 an HTTP Request Smuggling was possible

Vulnerability class: HTTP Request Smuggling

EPSS: 0.000 (0.1th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

Affected products

Jetbrains Ktor — versions 0

Weakness classification (CWE)

CWE-444 — Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling)

Public proof-of-concept exploits

fkie-cad/nvd-json-data-feeds

References

www.jetbrains.com/privacy-security/issues-fixed/

Frequently asked questions

What is CVE-2025-29904?: CVE-2025-29904 is a medium-severity vulnerability in Jetbrains Ktor, classified under Inconsistent Interpretation of HTTP Requests (HTTP Request/Response Smuggling). CVSS score: 5.3/10. Published 2025-03-12.
How severe is CVE-2025-29904?: Medium severity. CVSS v3 base score is 5.3 out of 10.
Is CVE-2025-29904 known to be exploited?: 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.