SB2026040967 - Fedora 44 update for libpng
Published: April 9, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) Use-after-free (CVE-ID: CVE-2026-33416)
The vulnerability allows a remote attacker to execute arbitrary code.
The vulnerability exists due to use-after-free in png_set_tRNS and png_set_PLTE when processing a crafted PNG file and subsequent decoding after png_free_data() or repeated setter calls. A remote attacker can supply a specially crafted PNG file to execute arbitrary code.
User interaction is required to open or process the crafted PNG file, and exploitation affects applications that free PNG data between png_read_info() and png_read_update_info().
2) Heap-based buffer overflow (CVE-ID: CVE-2026-25646)
The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error within the png_set_quantize() API function. A remote attacker can pass specially crafted PNG image to the application, trigger a heap-based buffer overflow and execute arbitrary code on the target system.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
3) Out-of-bounds read (CVE-ID: CVE-2026-33636)
The vulnerability allows a remote attacker to cause a denial of service, disclose sensitive information, and corrupt memory.
The vulnerability exists due to out-of-bounds read and out-of-bounds write in the ARM/AArch64 Neon palette expansion path when decoding a crafted paletted PNG image with palette expansion enabled. A remote attacker can supply a specially crafted PNG image to cause a denial of service, disclose sensitive information, and corrupt memory.
Only builds targeting ARM/AArch64 with Neon enabled are affected. The issue is triggered for palette-based images during palette expansion, with the RGBA path requiring a tRNS chunk and the RGB path requiring no tRNS chunk. User interaction is required to open or process the crafted image.
Remediation
Install update from vendor's website.