CVE-2026-47254Public exploit

Application crash via out-of-bounds chunk index

Published Jul 21, 2026 · Updated Jul 21, 2026

Out-of-bounds read in libheif before 1.22.0 allows context-dependent attackers to crash applications via crafted HEIC sequences. Track::init_sample_timing_table() records m_chunks.size() as a valid timeline index when stco defines fewer chunks than stsz defines samples. Opening the file and iterating raw sequence samples is required; the confirmed effect is a crash, while adjacent heap reads depend on layout.

CVSS severity6.1
Medium
EPSS probability0.19%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in libheif before 1.22.0 allows context-dependent attackers to crash applications via crafted HEIC sequences. Track::init_sample_timing_table() records m_chunks.size() as a valid timeline index when stco defines fewer chunks than stsz defines samples. Opening the file and iterating raw sequence samples is required; the confirmed effect is a crash, while adjacent heap reads depend on layout.

The record

CVE
CVE-2026-47254
Published
Jul 21, 2026
Updated
Jul 21, 2026
Vendor
Struktur AG
Product
libheif
Classifications
CWE-125, T1204.002
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 21, 2026CVE publishedPublication date reported by the CVE source.
  2. Jul 21, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 1.22.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Struktur AG · libheifversion=< 1.22.0

Published CVSS scores

6.1GitHub, Inc.CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-125Out-of-bounds Read
T1204.002Malicious File

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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