What is CVE-2026-5545?

CVE-2026-5545 is a medium-severity vulnerability in Curl, classified under Insufficient Session Expiration. CVSS score: 6.5/10. Published 2026-05-13.

How severe is CVE-2026-5545?

Medium severity. CVSS v3 base score is 6.5 out of 10.

Vulnerability in Curl

CVE-2026-5545

libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTP(S) request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of recent connections so that subse…

EPSS: 0.000 (11.2th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 6.5 (Medium). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:H/A:N.

Affected products

Curl — versions 8.19.0, 8.18.0, 8.17.0
Haxx Curl

Weakness classification (CWE)

CWE-613 — Insufficient Session Expiration

References

2499f714-1537-4658-8207-48ae4bb9eae9 (Vendor Advisory)
2499f714-1537-4658-8207-48ae4bb9eae9 (Patch, Vendor Advisory)
2499f714-1537-4658-8207-48ae4bb9eae9 (Exploit, Third Party Advisory, Issue Tracking)

Frequently asked questions

What is CVE-2026-5545?: CVE-2026-5545 is a medium-severity vulnerability in Curl, classified under Insufficient Session Expiration. CVSS score: 6.5/10. Published 2026-05-13.
How severe is CVE-2026-5545?: Medium severity. CVSS v3 base score is 6.5 out of 10.