CVE-2026-86413: Negotiate credentials sent to redirected origin
Negotiate credentials sent to redirected origin
Other sources
When using an ambient user in a first transfer doing Negotiate authentication and asked to follow redirects, curl could pass on its credential details to an unrelated second origin when asked to redirect there.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
alpine/curlto a version that resolves this vulnerability.Fixed in 8.23.0-r0 - Upgrade
Upgrade
debian/curlto a version that resolves this vulnerability.Fixed in 7.88.1-10+deb12u15Fixed in 7.88.1-10+deb12u5Fixed in 8.14.1-2+deb13u5Fixed in 8.14.1-2+deb13u7Fixed in 8.23.0-1
Event History
Frequently Asked Questions
Who is exposed to this issue?
Users of curl are exposed when a first transfer uses an ambient user with Negotiate authentication and curl follows a redirect to a different, unrelated origin.
What must an attacker control or cause for exploitation?
The attacker needs the client to receive a redirect during a Negotiate-authenticated transfer and have curl follow that redirect to an unrelated second origin. The provided information does not specify any other prerequisites.
Are credential details sent to every redirected destination?
The described exposure is specifically a redirect from the original origin to an unrelated second origin while using an ambient user and Negotiate authentication. The data does not state that other authentication methods or non-redirected requests are affected.