CVE-2026-84383
- Published18 Sept 2026
Description
libheif is a HEIF and AVIF file format decoder and encoder. From 1.22.0 until 1.23.2, a crafted HEIF, HEIC, or AVIF item graph using nested iden and auxl references can make HeifPixelImage::transfer_channel_from_image_as() append duplicate Alpha planes with different bit depths to m_storage. HeifPixelImage::scale_nearest_neighbor() in libheif/image/pixelimage.cc allocates the destination Alpha plane using the first plane's 8-bit depth, then iterates a later 10-bit or 12-bit Alpha component and writes uint16_t samples into the same 8-bit allocation. The output geometry controls the overflow extent and the encoded sample values control the data written, allowing a remote file processed by heif_decode_image() to cause a heap out-of-bounds write. This issue is fixed in version 1.23.2.
CVSS 3.1 breakdown
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HRemediation
No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.
References
Related CVEs
Recent high-severity vulnerabilities sharing a weakness type.
Frequently asked
Is CVE-2026-84383 being actively exploited?
CVE-2026-84383 is not in the CISA KEV catalog.
How severe is CVE-2026-84383?
CVE-2026-84383 has a CVSS 3.1 base score of 9.8, rated critical.
How do I fix CVE-2026-84383?
Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.
How Secuno handles this
Secuno correlates vulnerabilities like CVE-2026-84383 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.
Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.