Detections
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libcurl 8.11.0 < 8.21.0 HTTP/3 Early Data Information Disclosure (CVE-2026-9545)

high Nessus Plugin ID 326237

Synopsis

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

Description

The version of libcurl installed on the remote host is 8.11.0 prior to 8.21.0. It is, therefore, affected by an information disclosure vulnerability:

 - When libcurl returns to a hostname with a cached SSL session and early data enabled, libcurl might send the request bytes before enforcing the certificate verification failure, potentially leaking sensitive information. (CVE-2026-9545)

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

Solution

Upgrade libcurl to version 8.21.0 or later.

See Also

https://curl.se/docs/CVE-2026-9545.html

Plugin Details

Severity: High

ID: 326237

File Name: libcurl_CVE-2026-9545.nasl

Version: 1.1

Type: Local

Agent: windows, macosx, unix

Family: Misc.

Published: 7/10/2026

Updated: 7/10/2026

Configuration: Enable thorough checks (optional)

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3

Percentile: 23.75

CVSS v2

Risk Factor: High

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:N/A:N

CVSS Score Source: CVE-2026-9545

CVSS v3

Risk Factor: High

Base Score: 7.5

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

Vulnerability Information

CPE: cpe:/a:haxx:libcurl

Required KB Items: installed_sw/libcurl

Patch Publication Date: 6/24/2026

Vulnerability Publication Date: 6/24/2026

Reference Information

CVE: CVE-2026-9545

IAVA: 2026-A-0627