AlmaLinux 9.6 [TuxCare] Security Update: libsoup / libsoup-devel / libsoup-doc Multiple Vulnerabilities (ALMALINUX9.6:CLSA-2026:1792600325)

critical Nessus Plugin ID 369956

Synopsis

The AlmaLinux host is missing one or more security updates.

Description

The AlmaLinux 9.6 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1792600325 advisory.

- A flaw was found in libsoup. The soup_uri_decode_data_uri() function incorrectly treated base64 data-URI payloads as NUL-terminated strings when calling g_base64_decode_inplace(). If the percent-decoded payload contained embedded NUL bytes, the decoded length could remain uninitialized and be used as the size of the returned GBytes. This can lead to an out-of-bounds read or application crash when processing a crafted data URI. (CVE-2026-102555)

- A flaw was found in libsoup. When handling an incoming WebSocket Pong frame, SoupWebsocketConnection emitted the ::pong signal with a GByteArray pointer even though the signal is declared to pass a GBytes.
Applications connecting a handler that follows the documented GBytes API can trigger heap corruption or a crash upon receiving a crafted Pong. (CVE-2026-102556)

- A flaw was found in libsoup. When reassembling fragmented WebSocket messages into a GByteArray, libsoup did not adequately cap total message size against the limits of the underlying buffer type. A remote peer could send fragments that caused size truncation while the implementation still used the full length, leading to heap corruption or a crash. (CVE-2026-102557)

- A flaw was found in libsoup. When max-incoming-payload-size is unlimited (0), SoupWebsocketConnection could grow its incoming GByteArray based on an attacker-controlled frame length until the length wrapped, causing a heap buffer overflow while reading frame data. (CVE-2026-102558)

- A flaw was found in libsoup. When constructing a masked WebSocket client frame for a very large outgoing payload, size values passed to GByteArray allocation APIs could be truncated while the masking routine still used the full length, causing a heap buffer overflow. (CVE-2026-102559)

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 ALMALINUX9.6:CLSA-2026:1792600325.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1792600325

http://www.nessus.org/u?cf2012bb

Plugin Details

Severity: Critical

ID: 369956

File Name: tuxcare_alma_linux_9.6_CLSA-2026-1792600325.nasl

Version: 1.1

Type: Local

Published: 10/21/2026

Updated: 10/21/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 5.9

Percentile: 96.19

Vendor

Vendor Severity: Critical

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 7.4

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

CVSS Score Source: CVE-2026-102560

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 8.5

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:U/RL:O/RC:C

Vulnerability Information

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

Exploit Ease: No known exploits are available

Patch Publication Date: 10/21/2026

Vulnerability Publication Date: 9/29/2026

Reference Information

CVE: CVE-2026-102555, CVE-2026-102556, CVE-2026-102557, CVE-2026-102558, CVE-2026-102559, CVE-2026-102560

CLSA: 2026:1792600325