CVE-2026-86409: high-severity vulnerability in curl
stale SigV4 headers sent unintended
Published · Updated
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21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.1epss 1.1%
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.
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected products
curl · curlRelated CVEs — curl
In the same product, most dangerous first.