Rocky Linux 9.6 [TuxCare] Security Update: libpng15 (ALMALINUX9.6:CLSA-2026:1776422998)

high Nessus Plugin ID 362246

Synopsis

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

Description

The Rocky Linux 9.6 host has a package installed that is affected by a vulnerability as referenced in the TuxCare ALMALINUX9.6:CLSA-2026:1776422998 advisory.

- LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. In versions 1.2.1 through 1.6.55, `png_set_tRNS` and `png_set_PLTE` each alias a heap-allocated buffer between `png_struct` and `png_info`, sharing a single allocation across two structs with independent lifetimes. The `trans_alpha` aliasing has been present since at least libpng 1.0, and the `palette` aliasing since at least 1.2.1. Both affect all prior release lines `png_set_tRNS` sets `png_ptr->trans_alpha = info_ptr->trans_alpha` (256-byte buffer) and `png_set_PLTE` sets `info_ptr->palette = png_ptr->palette` (768-byte buffer). In both cases, calling `png_free_data` (with `PNG_FREE_TRNS` or `PNG_FREE_PLTE`) frees the buffer through `info_ptr` while the corresponding `png_ptr` pointer remains dangling. Subsequent row-transform functions dereference and, in some code paths, write to the freed memory. A second call to `png_set_tRNS` or `png_set_PLTE` has the same effect, because both functions call `png_free_data` internally before reallocating the `info_ptr` buffer. Version 1.6.56 fixes the issue. (CVE-2026-33416)

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

Solution

Update the affected libpng15 package based on the guidance in TuxCare advisory ALMALINUX9.6:CLSA-2026:1776422998.

See Also

https://cve.tuxcare.com/els/releases/CLSA-2026:1776422998

http://www.nessus.org/u?8ded4ca6

Plugin Details

Severity: High

ID: 362246

File Name: tuxcare_rocky_linux_9.6_CLSA-2026-1776422998.nasl

Version: 1.1

Type: Local

Published: 10/1/2026

Updated: 10/1/2026

Supported Sensors: Nessus Agent, Continuous Assessment, Nessus

Risk Information

VPR

Risk Factor: High

Score: 7.9

Percentile: 99.35

Vendor

Vendor Severity: Important

CVSS v2

Risk Factor: High

Base Score: 7.6

Temporal Score: 6

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

CVSS Score Source: CVE-2026-33416

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:R/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/cpu, Host/RockyLinux/release, Host/RockyLinux/rpm-list, Host/OS/extended-third-party

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 4/17/2026

Vulnerability Publication Date: 3/10/2026

Reference Information

CVE: CVE-2026-33416

CLSA: 2026:1776422998