CVE-2026-47178Public exploit

Code execution via chroma row offset miscalculation

Published Jul 21, 2026 · Updated Jul 21, 2026

Heap out-of-bounds write in libheif 1.19.0 through 1.21.2 allows local users to corrupt process memory via a crafted HEIF file. In unc_decoder_component_interleave::decode_tile(), a full-resolution row origin is applied to an already halved 4:2:0 chroma stride, writing beyond the chroma plane. An application must be built with WITH_UNCOMPRESSED_CODEC enabled and decode the file; the overwrite enables a controlled crash and attacker-directed virtual dispatch.

CVSS severity7.8
High
EPSS probability0.20%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
Coverage for this vulnerability

See if you're affected

Explore vulnerability checks for your environment with Hinoki.

Book a demo

Summary

What happened

Heap out-of-bounds write in libheif 1.19.0 through 1.21.2 allows local users to corrupt process memory via a crafted HEIF file. In unc_decoder_component_interleave::decode_tile(), a full-resolution row origin is applied to an already halved 4:2:0 chroma stride, writing beyond the chroma plane. An application must be built with WITH_UNCOMPRESSED_CODEC enabled and decode the file; the overwrite enables a controlled crash and attacker-directed virtual dispatch.

The record

CVE
CVE-2026-47178
Published
Jul 21, 2026
Updated
Jul 21, 2026
Vendor
Struktur AG
Product
libheif
Classifications
CWE-787, T1203
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

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

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

  1. Affected versionversion=>= 1.19.0, < 1.22.0

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

Struktur AG · libheifversion=>= 1.19.0, < 1.22.0

Published CVSS scores

7.8NIST NVDCVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
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

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1203Exploitation for Client Execution

Public exploit references

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

Technologies

Your stack

See the directory against your own environment.

Your stack

Check the software in your environment

Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.

Book a demo