What’s Vulnerable › Vulnerabilities

CVE-2026-84451: libheif: Incomplete fix for CVE-2026-62292 leaves libheif vulnerable to an out-of-bounds read

• Severity: medium (CVSS 6.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-18 · updated 2026-09-24
• Weakness: CWE-125

Description

libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.3, the no-icef full-item branch of unc_decoder::get_compressed_image_data_uncompressed() in libheif/codecs/uncompressed/unc_decoder.cc retains an addition-based range check that can wrap when a crafted uncompressed tile grid produces a large range_start_offset and range_size. The overflow makes the bounds comparison pass and allows heif_image_handle_decode_image_tile() to call memcpy() with an invalid source pointer and a very large length when decoding a valid high-index advertised tile. This incomplete remediation of CVE-2026-62292 can reliably crash tile-processing applications, while whole-image decoding is not claimed to reach the demonstrated path. This issue is fixed in version 1.23.3.

Affected products

• strukturag libheif: from 1.19.0, < 1.23.3

References

• https://github.com/strukturag/libheif/commit/8bfed9a9ed008e4ef28abc736284a90d3cba754f
• https://github.com/strukturag/libheif/releases/tag/v1.23.3
• https://github.com/strukturag/libheif/security/advisories/GHSA-hh47-fhqr-cj2r

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