Login Request a demo
Unscored severity · published Oct 20, 2026
CVE-2026-86414
leaking host credentials to HTTP proxy
–
CVSS
0.3%
EPSS
No
On KEV
Description
An HTTP proxy can trick libcurl into sending the origin's credentials (Basic password, or a Negotiate/Kerberos ticket) to the proxy itself, by answering the `CONNECT` tunnel request with 401 `WWW-Authenticate:` instead of the expected 407 `Proxy-Authenticate:`.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.3% · higher than 18% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CU
curl · curl
8.22.0 through 8.22.0; 8.21.0 through 8.21.0; 8.20.0 through 8.20.0; 8.19.0 through 8.19.0; 8.18.0 through 8.18.0; 8.17.0 through 8.17.0; +34 more · source: vendor
Affected product
CU
curl
curl
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86414
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-86414
curl.se
https://curl.se/docs/CVE-2026-86414.html
curl.se
https://curl.se/docs/CVE-2026-86414.json
hackerone.com
https://hackerone.com/reports/3993566
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