Expired Pointer Dereference Affecting libpng-debuginfo package, versions <2:1.6.37-10.amzn2023.0.12


Severity

Recommended
0.0
high
0
10

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.04% (13th percentile)

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  • Snyk IDSNYK-AMZN2023-LIBPNGDEBUGINFO-16067889
  • published15 Apr 2026
  • disclosed26 Mar 2026

Introduced: 26 Mar 2026

NewCVE-2026-33416  (opens in a new tab)
CWE-825  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 libpng-debuginfo to version 2:1.6.37-10.amzn2023.0.12 or higher.
This issue was patched in ALAS2023-2026-1563.

NVD Description

Note: Versions mentioned in the description apply only to the upstream libpng-debuginfo package and not the libpng-debuginfo package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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-&gt;trans_alpha = info_ptr-&gt;trans_alpha (256-byte buffer) and png_set_PLTE sets info_ptr-&gt;palette = png_ptr-&gt;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.

CVSS Base Scores

version 3.1