VulnerabilityDeferred

CVE-2026-62291

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.

MEDIUM 5.3EPSS 0.13%

Does this matter?

Lower severity and a low EPSS score (0.13%). Track it; it rarely justifies an emergency change on its own.

Description

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.

CVSS 3.1: 5.3 MEDIUMCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
EPSS: 0.13% probability · 3th percentile
CISA KEV: Not listed
Weakness: CWE-125, CWE-787
Source: security-advisories@github.com

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.