CVE-2026-62291

libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.0 and earlier, a crafted image sequence with a 2x2 primary plane and a 256x256 auxiliary alpha plane can cause attacker-controlled heap corruption during a normal decode and re-encode workflow. Track_Visual::decode_next_image_sample() calls transfer_channel_from_image_as() without checking that the auxiliary alpha dimensions match the main frame. The resulting inconsistent image reaches heif_track_decode_next_image() and then heif_context_encode_image(). In unc_encoder::encode(), unc_encoder_component_interleave::encode_tile() sizes its buffer with compute_tile_data_size_bytes() using the primary dimensions but copies each component using its actual plane dimensions. The oversized alpha plane is therefore copied beyond the allocation, causing an out-of-bounds write; the inverse size mismatch can also produce an out-of-bounds read. This issue is fixed in version 1.23.1.

These are all security issues fixed in the gdk-pixbuf-loader-libheif-1.23.1-1.1 package on the GA media of openSUSE Tumbleweed.

This update for libheif fixes the following issues:

Update to version 1.23.1 (jsc#PED-16355).

Security issues fixed:

• CVE-2026-62289: integer underflow in Fraction constructor via double clap transform application (bsc#1273079).
• CVE-2026-62291: heap out-of-bounds write in the uncompressed encoder when writing images with mismatched auxiliary alpha dimensions (bsc#1273080).
• CVE-2026-62292: out-of-bounds read in uncompressed unci tile range slicing (bsc#1273081).
• CVE-2026-62377: reachable assertion in HeifContext::get_track() aborts on a valid-but-empty HEIF sequence file (bsc#1273082).
• Heap out-of-bounds write in the uncompressed encoder for RRGGBB images with interleaved bit-depth <= 8 (bsc#1273083).

Changes for libheif:

• Version 1.23.1
  • FFmpeg decoder plugin gains AV1, VVC, JPEG, and JPEG 2000/HTJ2K decoding.
  • SVT-AV1 encoder: new tune=iq and ms-ssim tune parameters.
  • C++ API: added getters/setters for the CLLI and MDCV HDR metadata boxes.
  • Sequence decoder now scales the alpha auxiliary track to the main image size.
  • Fixed pixi box writing for multi-channel images.
  • Corrected the placement of the TAI clock_type field into the top 2 bits.
  • Empty/unset plugin directory is no longer scanned.

This update for libheif fixes the following issues:

Update to version 1.23.1 (jsc#PED-16355).

Security issues fixed:

• CVE-2026-62289: integer underflow in Fraction constructor via double clap transform application (bsc#1273079).
• CVE-2026-62291: heap out-of-bounds write in the uncompressed encoder when writing images with mismatched auxiliary alpha dimensions (bsc#1273080).
• CVE-2026-62292: out-of-bounds read in uncompressed unci tile range slicing (bsc#1273081).
• CVE-2026-62377: reachable assertion in HeifContext::get_track() aborts on a valid-but-empty HEIF sequence file (bsc#1273082).
• Heap out-of-bounds write in the uncompressed encoder for RRGGBB images with interleaved bit-depth <= 8 (bsc#1273083).

Changes for libheif:

• Version 1.23.1
  • FFmpeg decoder plugin gains AV1, VVC, JPEG, and JPEG 2000/HTJ2K decoding.
  • SVT-AV1 encoder: new tune=iq and ms-ssim tune parameters.
  • C++ API: added getters/setters for the CLLI and MDCV HDR metadata boxes.
  • Sequence decoder now scales the alpha auxiliary track to the main image size.
  • Fixed pixi box writing for multi-channel images.
  • Corrected the placement of the TAI clock_type field into the top 2 bits.
  • Empty/unset plugin directory is no longer scanned.

This update for libheif fixes the following issues:

Update to version 1.23.1 (jsc#PED-16355).

Security issues fixed:

• CVE-2026-62289: integer underflow in Fraction constructor via double clap transform application (bsc#1273079).
• CVE-2026-62291: heap out-of-bounds write in the uncompressed encoder when writing images with mismatched auxiliary alpha dimensions (bsc#1273080).
• CVE-2026-62292: out-of-bounds read in uncompressed unci tile range slicing (bsc#1273081).
• CVE-2026-62377: reachable assertion in HeifContext::get_track() aborts on a valid-but-empty HEIF sequence file (bsc#1273082).
• Heap out-of-bounds write in the uncompressed encoder for RRGGBB images with interleaved bit-depth <= 8 (bsc#1273083).

Changes for libheif:

• Version 1.23.1
  • FFmpeg decoder plugin gains AV1, VVC, JPEG, and JPEG 2000/HTJ2K decoding.
  • SVT-AV1 encoder: new tune=iq and ms-ssim tune parameters.
  • C++ API: added getters/setters for the CLLI and MDCV HDR metadata boxes.
  • Sequence decoder now scales the alpha auxiliary track to the main image size.
  • Fixed pixi box writing for multi-channel images.
  • Corrected the placement of the TAI clock_type field into the top 2 bits.
  • Empty/unset plugin directory is no longer scanned.

Feng Ning discovered that libheif incorrectly handled certain image transforms. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, and Ubuntu 22.04 LTS. (CVE-2026-62289)

Ali Firas discovered that libheif incorrectly handled certain images. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. This issue only affected Ubuntu 24.04 LTS. (CVE-2026-62291)

Ali Firas discovered that libheif incorrectly handled certain images. An attacker could possibly use this issue to cause a denial of service or execute arbitrary code. (CVE-2026-62291)

Dmitrijs Trizna discovered that libheif incorrectly handled certain image sequences. An attacker could possibly use this issue to cause a denial of service. (CVE-2026-62377)