Vulnerability details

CVE-2026-86413

curl curl

Negotiate credentials sent to redirected origin

CVSS 3.1
9.1Critical

Official description

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.

CVSS scores

ScoreVersionSourceVector
9.1Critical 3.1 CISA ADP / Vulnrichment (CISA-ADP) CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

Affected products

VendorProductVersionsSource
curl curl 8.21.0 ≤ v ≤ 8.21.0 CVEProject cvelistV5 (CNA)
curl curl 8.22.0 ≤ v ≤ 8.22.0 CVEProject cvelistV5 (CNA)

References and advisories

3
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Details

Published
2026-10-20
Last updated
2026-10-30
State
Published
Assigner (CNA)
curl

Exploit prediction (EPSS)

0.73%
Probability of exploitation in 30 days
54.4%
Percentile (among all CVEs)

SSVC assessment (CISA)

Automatable
Yes
Exploitation
Proof of concept
Technical impact
Total

Weaknesses (CWE)

  • CWE-201
    Insertion of Sensitive Information Into Sent Data