Уязвимости libpng1.6

UBUNTU-CVE-2026-46675

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

• Обновитесь до 1.6.20-2ubuntu0.1~esm5

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

• Обновитесь до 1.6.20-2ubuntu0.1~esm4

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->

• Обновитесь до 1.6.20-2ubuntu0.1~esm4

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.

• Обновитесь до 1.6.20-2ubuntu0.1~esm3

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.

• Обновитесь до 1.6.20-2ubuntu0.1~esm3

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.

• Обновитесь до 1.6.20-2ubuntu0.1~esm3

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.

• Обновитесь до 1.6.20-2ubuntu0.1~esm2

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.

• Обновитесь до 1.6.20-2ubuntu0.1~esm2

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

• Обновитесь до 1.6.20-2ubuntu0.1~esm2

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.

• Обновитесь до 1.6.20-2ubuntu0.1~esm2

CVE-2017-12652

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

• Обновитесь до 1.6.20-2ubuntu0.1~esm1

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.

• Обновитесь до 1.6.20-2ubuntu0.1~esm4

CVE-2019-6129

png_create_info_struct in png.c in libpng 1.6.36 has a memory leak, as demonstrated by pngcp. NOTE: a third party has stated "I don't think it is libpng's job to free this buffer.

CVE-2018-14048

An issue has been found in libpng 1.6.34. It is a SEGV in the function png_free_data in png.c, related to the recommended error handling for png_read_image.

• Обновитесь до 1.6.20-2ubuntu0.1~esm1

CVE-2016-10087

The png_set_text_2 function in libpng 0.71 before 1.0.67, 1.2.x before 1.2.57, 1.4.x before 1.4.20, 1.5.x before 1.5.28, and 1.6.x before 1.6.27 allows context-dependent attackers to cause a NULL pointer dereference vectors involving loading a text chunk into a png structure, removing the text, and then adding another text chunk to the structure.

• Обновитесь до 1.6.20-2ubuntu0.1~esm4