What is CVE-2026-43968?

CVE-2026-43968 is a medium-severity vulnerability in Ninenines Cowlib, classified under CRLF Injection. CVSS score: 4.0/10. Published 2026-05-11.

How severe is CVE-2026-43968?

Medium severity. CVSS v3 base score is 4.0 out of 10.

Vulnerability in Ninenines Cowlib

CVE-2026-43968

Improper Neutralization of CRLF Sequences ('CRLF Injection') vulnerability in ninenines cowlib allows SSE event splitting and injection via unvalidated field values. cow_sse:event/1 in cowlib guards the id and event fields against \n but…

Vulnerability class: CRLF Injection

EPSS: 0.000 (11.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.0 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:N/I:L/A:N.

Affected products

Ninenines Cowlib — versions 2.6.0, 93b2b897cde238506c803faad4d1602d79dba7c9

Weakness classification (CWE)

CWE-93 — CRLF Injection

References

6b3ad84c-e1a6-4bf7-a703-f496b71e49db (related, Vendor Advisory, third-party-advisory)
6b3ad84c-e1a6-4bf7-a703-f496b71e49db (related, Third Party Advisory)
6b3ad84c-e1a6-4bf7-a703-f496b71e49db (Patch, patch)

Frequently asked questions

What is CVE-2026-43968?: CVE-2026-43968 is a medium-severity vulnerability in Ninenines Cowlib, classified under CRLF Injection. CVSS score: 4.0/10. Published 2026-05-11.
How severe is CVE-2026-43968?: Medium severity. CVSS v3 base score is 4.0 out of 10.