CentOS Linux 8.4 [TuxCare] Security Update: curl / curl-minimal / libcurl / libcurl-devel / libcurl-minimal Multiple Vulnerabilities (CENTOS8.4:CLSA-2026:1783937591)

critical Nessus Plugin ID 361055

Synopsis

The CentOS Linux host is missing one or more security updates.

Description

The CentOS Linux 8.4 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare CENTOS8.4:CLSA-2026:1783937591 advisory.

- Successfully using libcurl to do a transfer to a specific HTTP origin (`hostA`) with **Digest** authentication and then changing the origin to a different one (`hostB`) for a second transfer, reusing the same handle, makes libcurl wrongly pass on the `Authorization:` header field meant for `hostA`, to `hostB`. (CVE-2026-11856)

- When reusing a libcurl handle for sequential transfers driven by environment-variable proxy configuration, libcurl fails to clear the proxy authentication state between requests. Specifically, if the initial transfer authenticates against `proxyA` using Digest auth, a subsequent transfer routed through `proxyB` erroneously leaks the `Proxy-Authorization:` header intended solely for `proxyA`. (CVE-2026-8927)

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 affected packages based on the guidance in TuxCare advisory CENTOS8.4:CLSA-2026:1783937591.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1783937591

http://www.nessus.org/u?6f7b1b03

Plugin Details

Severity: Critical

ID: 361055

File Name: tuxcare_centos_8.4_CLSA-2026-1783937591.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 10/1/2026

Updated: 10/1/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.9

Percentile: 96.5

Vendor

Vendor Severity: Moderate

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.8

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

CVSS Score Source: CVE-2026-11856

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.8

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

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

Vulnerability Information

Required KB Items: Host/local_checks_enabled, Host/CentOS/release, Host/CentOS/rpm-list, Host/OS/extended-third-party

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 7/13/2026

Vulnerability Publication Date: 6/25/2026

Reference Information

CVE: CVE-2026-11856, CVE-2026-8927

CLSA: 2026:1783937591