Detections
Analytics
CentOS Linux 6 [TuxCare] Security Update: libpng / libpng-devel / libpng-static Multiple Vulnerabilities (CENTOS6:CLSA-2026:1792994241)
high Nessus Plugin ID 373905
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Synopsis
The CentOS Linux host is missing one or more security updates.Description
The CentOS Linux 6 host has packages installed that are affected by multiple vulnerabilities as referenced in the TuxCare CENTOS6:CLSA-2026:1792994241 advisory.- The png_set_text_2 function in libpng 0.71 before 1.0.67, 1.2.x before 1.2.57, 1.4.x before 1.4.20, 1.5.x before 1.5.28, and 1.6.x before 1.6.27 allows context-dependent attackers to cause a NULL pointer dereference vectors involving loading a text chunk into a png structure, removing the text, and then adding another text chunk to the structure. (CVE-2016-10087)
- LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.55, an out-of-bounds read vulnerability exists in the png_set_quantize() API function. When the function is called with no histogram and the number of colors in the palette is more than twice the maximum supported by the user's display, certain palettes will cause the function to enter into an infinite loop that reads past the end of an internal heap-allocated buffer.
The images that trigger this vulnerability are valid per the PNG specification. This vulnerability is fixed in 1.6.55. (CVE-2026-25646)
- 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 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 CENTOS6:CLSA-2026:1792994241.See Also
Plugin Details
Severity: High
ID: 373905
File Name: tuxcare_centos_6_CLSA-2026-1792994241.nasl
Version: 1.1
Type: Local
Agent: unix
Family: CentOS Local Security Checks
Published: 10/29/2026
Updated: 10/29/2026
Supported Sensors: Nessus Agent, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus
Risk Information
VPR
Risk Factor: High
Score: 7.7
Percentile: 98.93
Vendor
Vendor Severity: Important
CVSS v2
Risk Factor: Medium
Base Score: 5
Temporal Score: 3.9
Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:P
CVSS Score Source: CVE-2016-10087
CVSS v3
Risk Factor: High
Base Score: 8.1
Temporal Score: 7.3
Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C
CVSS Score Source: CVE-2026-25646
CVSS v4
Risk Factor: High
Base Score: 8.3
Threat Score: 7
Threat Vector: CVSS:4.0/E:P
Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:L/VI:L/VA:H/SC:N/SI:N/SA:N
CVSS Score Source: CVE-2026-25646
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: 10/26/2026
Vulnerability Publication Date: 12/29/2016
Reference Information
CVE: CVE-2016-10087, CVE-2026-25646, CVE-2026-33416
CLSA: 2026:1792994241