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VULNERABILITIES

CVE-2026-86409 Details

Description

Setting `CURLOPT_AWS_SIGV4` to NULL but does not disable SigV4 authentication, contrary to expectations and documentation. A subsequent transfer on the same handle still sends an `Authorization: AWS4-HMAC-SHA256` header to whatever URL isset next, leaking state information.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: CISA-ADPCVSS-B:8.1 HIGHVector:CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://hackerone.com/reports/3973135 CISA-ADP
https://curl.se/docs/CVE-2026-86409.html curl
https://curl.se/docs/CVE-2026-86409.json curl
https://hackerone.com/reports/3973135 curl

Weakness Enumeration

CWE-IDCWE NameSource
CWE-201Insertion of Sensitive Information Into Sent DataCISA-ADP

Affected Products

No affected product data is available for this CVE.

Change History

2 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-86409
NVD Published Date:
Oct 20, 2026
NVD Last Modified:
Oct 29, 2026
Source:
curl