Detections
Analytics

Curl 7.75.0 < 8.22.0 SigV4 Header Leak

medium Nessus Plugin ID 371147

Synopsis

The remote host has a program that is affected by an information disclosure vulnerability.

Description

The version of curl installed on the remote host is 7.75.0 prior to 8.22.0. It is, therefore, affected by an information disclosure vulnerability:

 - 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 is set next, leaking state information. (CVE-2026-86409)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

Solution

Upgrade Curl to version 8.22.0 or later.

See Also

https://curl.se/docs/CVE-2026-86409.html

Plugin Details

Severity: Medium

ID: 371147

File Name: curl_CVE-2026-86409.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 10/23/2026

Updated: 10/23/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

CVSS Score Rationale: Score from an analysis done by tenable

VPR

Risk Factor: Medium

Score: 4.9

Percentile: 58.46

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Vulnerability Information

CPE: cpe:/a:haxx:curl

Required KB Items: installed_sw/Curl

Patch Publication Date: 9/2/2026

Vulnerability Publication Date: 10/14/2026

Reference Information

CVE: CVE-2026-86409

IAVA: 2026-A-1143