RHEL 9 : curl (RHSA-2026:55439)

high Nessus Plugin ID 335959

Synopsis

The remote Red Hat host is missing one or more security updates for curl.

Description

The remote Redhat Enterprise Linux 9 host has packages installed that are affected by multiple vulnerabilities as referenced in the RHSA-2026:55439 advisory.

The curl packages provide the libcurl library and the curl utility for downloading files from servers using various protocols, including HTTP, FTP, and LDAP.

Security Fix(es):

* curl: curl: Authentication bypass due to incorrect connection reuse with Negotiate authentication (CVE-2026-1965)

* curl: curl: Information disclosure via OAuth2 bearer token leakage during HTTP(S) redirect (CVE-2026-3783)

* curl: curl: Man-in-the-middle attack via SSH host key bypass (CVE-2026-9547)

* curl: curl: Insecure connection establishment due to TLS configuration mismatch (CVE-2026-8286)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

Tenable has extracted the preceding description block directly from the Red Hat Enterprise Linux security advisory.

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

Solution

Update the RHEL curl package based on the guidance in RHSA-2026:55439.

Plugin Details

Severity: High

ID: 335959

File Name: redhat-RHSA-2026-55439.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Red Hat Local Security Checks

Published: 8/17/2026

Updated: 8/17/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.7

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 9.4

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-9547

CVSS v3

Risk Factor: High

Base Score: 8.1

Temporal Score: 7.3

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

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

CVSS Score Source: CVE-2026-8286

Vulnerability Information

CPE: cpe:/o:redhat:enterprise_linux:9, cpe:/o:redhat:rhel_eus:9.8, p-cpe:/a:redhat:enterprise_linux:curl-minimal, p-cpe:/a:redhat:enterprise_linux:curl, p-cpe:/a:redhat:enterprise_linux:libcurl-devel, p-cpe:/a:redhat:enterprise_linux:libcurl-minimal, p-cpe:/a:redhat:enterprise_linux:libcurl

Required KB Items: Host/local_checks_enabled, Host/RedHat/release, Host/RedHat/rpm-list, Host/cpu

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 8/17/2026

Vulnerability Publication Date: 3/11/2026

Reference Information

CVE: CVE-2026-1965, CVE-2026-3783, CVE-2026-8286, CVE-2026-9547

CWE: 201, 295, 303, 347

RHSA: 2026:55439

Detections

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