CVE-2026-33021 libsixel: Use-after-free in sixel_encoder_encode_bytes()

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a use-after-free vulnerability in sixelencoderencodebytes because sixelframeinit stores the caller-owned pixel buffer pointer directly in frame-pixels without making a defensive copy...

CVE-2026-33021

CVE-2026-33021 (libsixel) is a use-after-free in sixel_encoder_encode_bytes() affecting libsixel 1.8.7 and earlier. The bug arises because sixel_frame_init() stores a caller-owned pixel buffer pointer directly in frame->pixels without copying. On a subsequent resize, sixel_frame_convert_to_rgb...

CVE-2026-33020 libsixel: Integer Overflow in write_png_to_file() leads to Heap-based Buffer Overflow

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow which leads to a heap buffer overflow via sixelframeconverttorgb888 in frame.c, where allocation size and pointer offset computations for palettised images PAL1, PAL...

CVE-2026-33020

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow which leads to a heap buffer overflow via sixelframeconverttorgb888 in frame.c, where allocation size and pointer offset computations for palettised images PAL1, PAL...

CVE-2026-33020 libsixel: Integer Overflow in write_png_to_file() leads to Heap-based Buffer Overflow

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow which leads to a heap buffer overflow via sixelframeconverttorgb888 in frame.c, where allocation size and pointer offset computations for palettised images PAL1, PAL...

CVE-2026-33020 libsixel: Integer Overflow in write_png_to_file() leads to Heap-based Buffer Overflow

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow which leads to a heap buffer overflow via sixelframeconverttorgb888 in frame.c, where allocation size and pointer offset computations for palettised images PAL1, PAL...

CVE-2026-33020

libsixel versions up to 1.8.7 are affected by an integer overflow in sixel_frame_convert_to_rgb888() that causes a heap buffer overflow when handling palettised images (PAL1, PAL2, PAL4). The allocation size and pointer arithmetic use int, leading to an undersized heap allocation and negative off...

CVE-2026-33019

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INTMAX are accepted without overflow-safe bounds...

CVE-2026-33019 libsixel: Integer overflow leads to Out-of-bounds Read in img2sixel

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INTMAX are accepted without overflow-safe bounds...

CVE-2026-33019

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INTMAX are accepted without overflow-safe bounds...

CVE-2026-33019 libsixel: Integer overflow leads to Out-of-bounds Read in img2sixel

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INTMAX are accepted without overflow-safe bounds...

CVE-2026-33019

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INTMAX are accepted without overflow-safe bounds...

EUVD-2026-22742

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INTMAX are accepted without overflow-safe bounds...

CVE-2026-33019 libsixel: Integer overflow leads to Out-of-bounds Read in img2sixel

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain an integer overflow leading to an out-of-bounds heap read in the --crop option handling of img2sixel, where positive coordinates up to INTMAX are accepted without overflow-safe bounds...

CVE-2026-33019

Summary: The issue affects libsixel versions up to 1.8.7 and prior, where the --crop handling in img2sixel can overflow when coordinates are large. In sixel_encoder_do_clip(), clip_w + clip_x overflows for clip_x = INT_MAX, bypassing bounds checks and allowing an unclamped coordinate to reach six...

CVE-2026-33018

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a Use-After-Free vulnerability via the loadgif function in fromgif.c, where a single sixelframet object is reused across all frames of an animated GIF and gifinitframe unconditionally...

CVE-2026-33018 libsixel: Use-After-Free in load_gif()

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a Use-After-Free vulnerability via the loadgif function in fromgif.c, where a single sixelframet object is reused across all frames of an animated GIF and gifinitframe unconditionally...

CVE-2026-33018

libsixel 1.8.7 and prior contain a heap use‑after‑free in load_gif() (fromgif.c): a single sixel_frame_t is reused across all frames of an animated GIF and gif_init_frame() frees/reallocates frame->pixels between frames regardless of reference counts. A callback using sixel_frame_get_pixels() ...

CVE-2026-33021: Use After Free

libsixel is a SIXEL encoder/decoder implementation derived from kmiya's sixel. Versions 1.8.7 and prior contain a use-after-free vulnerability in sixelencoderencodebytes because sixelframeinit stores the caller-owned pixel buffer pointer directly in frame-pixels without making a defensive copy...

PT-2026-32926

Name of the Vulnerable Software and Affected Versions libsixel versions prior to 1.8.7-r1 Description An integer overflow exists in the handling of the '--crop' option in img2sixel. When positive coordinates up to INT MAX are provided, the sixel encoder do clip function fails to perform...