Buffer Underflow 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
0.03% (10th percentile)

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  • Snyk IDSNYK-AMZN2023-LIBPNGDEBUGINFO-16067196
  • published15 Apr 2026
  • disclosed26 Mar 2026

Introduced: 26 Mar 2026

NewCVE-2026-33636  (opens in a new tab)
CWE-124  (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 1.6.36 through 1.6.55, an out-of-bounds read and write exists in libpng's ARM/AArch64 Neon-optimized palette expansion path. When expanding 8-bit paletted rows to RGB or RGBA, the Neon loop processes a final partial chunk without verifying that enough input pixels remain. Because the implementation works backward from the end of the row, the final iteration dereferences pointers before the start of the row buffer (OOB read) and writes expanded pixel data to the same underflowed positions (OOB write). This is reachable via normal decoding of attacker-controlled PNG input if Neon is enabled. Version 1.6.56 fixes the issue.

CVSS Base Scores

version 3.1