libpng1.6 vulnerabilities

UBUNTU-CVE-2026-46675

[Use-after-free of zlib input in `png_read_end` after incomplete zTXt, iTXt or iCCP decompression]

• Update to 1.6.59-1

LIBPNG: Chunk smuggling in push-mode APNG parser via unconsumed chunk body

LIBPNG is a reference library for use in applications that process PNG (Portable Network Graphics) raster image files. In version 1.8.0, three inter-frame chunk discard paths in the push-mode APNG parser clear the chunk-header flag without consuming the chunk body and CRC, allowing attacker-controlled bytes inside an ignored ancillary chunk to be reinterpreted as a fresh chunk header on the next call to `png_process_data`. Commit faf06924688b62d7c1654b5ceddedbde66ffadb4 fixes the issue.

• Update to 1.6.37-4

LIBPNG has a yse-after-free in png_set_PLTE, png_set_tRNS and png_set_hIST leading to corrupted chunk data and potential heap information disclosure

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.0.9 to before 1.6.57, passing a pointer obtained from png_get_PLTE, png_get_tRNS, or png_get_hIST back into the corresponding setter on the same png_struct/png_info pair causes the setter to read from freed memory and copy its contents into the replacement buffer. The setter frees the internal buffer before copying from the caller-supplied pointer, which now dangles. The freed region may contain stale data (producing silently corrupted chunk metadata) or data from subsequent heap allocations (leaki

• Update to 1.6.57-1

LIBPNG has ARM NEON Palette Expansion Out-of-Bounds Read on AArch64

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

• Update to 1.6.56-1

LIBPNG has use-after-free via pointer aliasing in `png_set_tRNS` and `png_set_PLTE`

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->

• Update to 1.6.56-1

pnggroup libpng pnm2png pnm2png.c do_pnm2png heap-based overflow

A flaw has been found in pnggroup libpng up to 1.6.55. Affected by this vulnerability is the function do_pnm2png of the file contrib/pngminus/pnm2png.c of the component pnm2png. This manipulation of the argument width/height causes heap-based buffer overflow. The attack is restricted to local execution. The exploit has been published and may be used. The project was informed of the problem early through an issue report but has not responded yet.

LIBPNG has a heap buffer overflow in png_set_quantize

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.

• Update to 1.6.55-1

CVE-2025-28164

Buffer Overflow vulnerability in libpng 1.6.43-1.6.46 allows a local attacker to cause a denial of service via png_create_read_struct() function.

• Update to 1.6.47-1

CVE-2025-28162

Buffer Overflow vulnerability in libpng 1.6.43-1.6.46 allows a local attacker to cause a denial of service via the pngimage with AddressSanitizer (ASan), the program leaks memory in various locations, eventually leading to high memory usage and causing the program to become unresponsive

• Update to 1.6.47-1

LIBPNG has an integer truncation causing heap buffer over-read in png_image_write_*

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.6.26 to 1.6.53, there is an integer truncation in the libpng simplified write API functions png_write_image_16bit and png_write_image_8bit causes heap buffer over-read when the caller provides a negative row stride (for bottom-up image layouts) or a stride exceeding 65535 bytes. The bug was introduced in libpng 1.6.26 (October 2016) by casts added to silence compiler warnings on 16-bit systems. This vulnerability is fixed in 1.6.54.

• Update to 1.6.54-1

LIBPNG has a heap buffer over-read in png_image_read_direct_scaled (regression from CVE-2025-65018 fix)

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From 1.6.51 to 1.6.53, there is a heap buffer over-read in the libpng simplified API function png_image_finish_read when processing interlaced 16-bit PNGs with 8-bit output format and non-minimal row stride. This is a regression introduced by the fix for CVE-2025-65018. This vulnerability is fixed in 1.6.54.

• Update to 1.6.54-1

LIBPNG has an out-of-bounds read in png_image_read_composite

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to 1.6.52, an out-of-bounds read vulnerability in libpng's simplified API allows reading up to 1012 bytes beyond the png_sRGB_base[512] array when processing valid palette PNG images with partial transparency and gamma correction. The PNG files that trigger this vulnerability are valid per the PNG specification; the bug is in libpng's internal state management. Upgrade to libpng 1.6.52 or later.

• Update to 1.6.52-1

LIBPNG is vulnerable to a heap buffer overflow in `png_combine_row` triggered via `png_image_finish_read`

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From version 1.6.0 to before 1.6.51, there is a heap buffer overflow vulnerability in the libpng simplified API function png_image_finish_read when processing 16-bit interlaced PNGs with 8-bit output format. Attacker-crafted interlaced PNG files cause heap writes beyond allocated buffer bounds. This issue has been patched in version 1.6.51.

• Update to 1.6.51-1

LIBPNG is vulnerable to a buffer overflow in `png_image_read_composite` via incorrect palette premultiplication

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From version 1.6.0 to before 1.6.51, an out-of-bounds read vulnerability exists in png_image_read_composite when processing palette images with PNG_FLAG_OPTIMIZE_ALPHA enabled. The palette compositing code in png_init_read_transformations incorrectly applies background compositing during premultiplication, violating the invariant component ≤ alpha × 257 required by the simplified PNG API. This issue has been patched in version 1.6.51.

• Update to 1.6.51-1

LIBPNG is vulnerable to a heap buffer over-read in `png_write_image_8bit` with grayscale+alpha or RGB/RGBA images

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. From version 1.6.0 to before 1.6.51, a heap buffer over-read vulnerability exists in libpng's png_write_image_8bit function when processing 8-bit images through the simplified write API with convert_to_8bit enabled. The vulnerability affects 8-bit grayscale+alpha, RGB/RGBA, and images with incomplete row data. A conditional guard incorrectly allows 8-bit input to enter code expecting 16-bit input, causing reads up to 2 bytes beyond allocated buffer boundaries. This issue has been patched in version 1.6.51

• Update to 1.6.51-1

LIBPNG is vulnerable to a heap buffer overflow in `png_do_quantize` via malformed palette index

LIBPNG is a reference library for use in applications that read, create, and manipulate PNG (Portable Network Graphics) raster image files. Prior to version 1.6.51, a heap buffer over-read vulnerability exists in libpng's png_do_quantize function when processing PNG files with malformed palette indices. The vulnerability occurs when palette_lookup array bounds are not validated against externally-supplied image data, allowing an attacker to craft a PNG file with out-of-range palette indices that trigger out-of-bounds memory access. This issue has been patched in version 1.6.51.

• Update to 1.6.51-1

CVE-2021-4214

A heap overflow flaw was found in libpngs' pngimage.c program. This flaw allows an attacker with local network access to pass a specially crafted PNG file to the pngimage utility, causing an application to crash, leading to a denial of service.

CVE-2017-12652

libpng before 1.6.32 does not properly check the length of chunks against the user limit.

• Update to 1.6.32-1

CVE-2018-14550

An issue has been found in third-party PNM decoding associated with libpng 1.6.35. It is a stack-based buffer overflow in the function get_token in pnm2png.c in pnm2png.

• Update to 1.6.37-1

CVE-2019-7317

png_image_free in png.c in libpng 1.6.x before 1.6.37 has a use-after-free because png_image_free_function is called under png_safe_execute.

• Update to 1.6.36-4