CVE-2026-86414
An HTTP proxy can trick libcurl into sending the origin's credentials (Basic password, or a…
- Risk score
- 63/100
- CVSS
- 9.1 v3.1
- Exploit chance (30 days)
- 0.3%
- Published
- 20 Oct 2026
Open in the live forecast Today's forecast
What to know
- What it is
- 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:.
- Affected
- See advisory
- Fix
- Apply the vendor's security update; see the linked advisory.
- Exploitation
- No known exploitation
Why it is Amber
- CVSS 9.1 critical
- Remotely exploitable without logging in
References
Original 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:`.
Last activity 20 Oct 2026. Patch Forecast updates every hour.