CVE-2026-86413

UNKNOWN 0.0

Negotiate credentials sent to redirected origin

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

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.

Vendor	curl
Product	curl
Published	Oct 20, 2026

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Affected Versions

curl / curl

8.22.0 ≤ 8.22.0 8.21.0 ≤ 8.21.0

References

NVD ↗ CVE.org ↗ EPSS Data ↗

curl.se: https://curl.se/docs/CVE-2026-86413.json curl.se: https://curl.se/docs/CVE-2026-86413.html hackerone.com: https://hackerone.com/reports/3993549

Credits

Stanislav Fort (Aisle Research) Stefan Eissing