Linux Distros Unpatched Vulnerability : CVE-2026-5545

medium Nessus Plugin ID 311003

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Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- libcurl might in some circumstances reuse the wrong connection when asked to do an authenticated HTTP(S) request after a Negotiate-authenticated one, when both use the same host. libcurl features a pool of recent connections so that subsequent requests can reuse an existing connection to avoid overhead. When reusing a connection a range of criteria must be met. Due to a logical error in the code, a request that was issued by an application could wrongfully reuse an existing connection to the same server that was authenticated using different credentials. An application that first uses Negotiate authentication to a server with `user1:password1` and then does another operation to the same server asking for any authentication method but for `user2:password2` (while the previous connection is still alive) - the second request gets confused and wrongly reuses the same connection and sends the new request over that connection thinking it uses a mix of user1's and user2's credentials when it is in fact still using the connection authenticated for user1... (CVE-2026-5545)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

Plugin Details

Severity: Medium

ID: 311003

File Name: unpatched_CVE_2026_5545.nasl

Version: 1.15

Type: Local

Agent: unix

Family: Misc.

Published: 4/29/2026

Updated: 9/21/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Low

Score: 3.5

Percentile: 51.79

CVSS v2

Risk Factor: Medium

Base Score: 5.5

Temporal Score: 5

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

CVSS Score Source: CVE-2026-5545

CVSS v3

Risk Factor: Medium

Base Score: 6.5

Temporal Score: 6.2

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

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

Vulnerability Information

CPE: cpe:/o:centos:centos:7, cpe:/o:centos:centos:8, cpe:/o:debian:debian_linux:12.0, cpe:/o:redhat:enterprise_linux:10, cpe:/o:redhat:enterprise_linux:6, cpe:/o:redhat:enterprise_linux:7, cpe:/o:redhat:enterprise_linux:8, cpe:/o:redhat:enterprise_linux:9, p-cpe:/a:centos:centos:curl-minimal, p-cpe:/a:centos:centos:curl, p-cpe:/a:centos:centos:libcurl-devel, p-cpe:/a:centos:centos:libcurl-minimal, p-cpe:/a:centos:centos:libcurl, p-cpe:/a:centos:centos:snphost, p-cpe:/a:centos:centos:trustee-guest-components, p-cpe:/a:centos:centos:trustee-kbs, p-cpe:/a:debian:debian_linux:curl, 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, p-cpe:/a:redhat:enterprise_linux:snphost, p-cpe:/a:redhat:enterprise_linux:trustee-guest-components, p-cpe:/a:redhat:enterprise_linux:trustee-kbs

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Available: true

Exploit Ease: Exploits are available

Reference Information

CVE: CVE-2026-5545

Detections

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