CVE-2026-33636
libpng: libpng: Information disclosure and denial of service via out-of-bounds read/write in Neon palette expansion
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · March 27, 2026
Updated · October 31, 2026
Description
A flaw was found in libpng. A remote attacker could exploit an out-of-bounds read and write vulnerability in the ARM/AArch64 Neon-optimized palette expansion path. This occurs when processing a final partial chunk of 8-bit paletted rows without verifying sufficient input pixels, leading to dereferencing pointers before the start of the row buffer and writing expanded pixel data to underflowed positions. This flaw can result in information disclosure and denial of service.
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.
CVSS / CWE
CVSS 3.1 · 7.6CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:H
CWE-124 · Buffer Underwrite ('Buffer Underflow')