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PatchSiren cyber security CVE debrief

CVE-2026-47178 strukturag CVE debrief

A heap out-of-bounds write vulnerability exists in libheif's uncompressed tile decoder. Versions 1.19.0 through 1.21.2 are affected. A crafted HEIF file (uncompressed `unci` codec, tiled, component-interleaved, 4:2:0) can trigger the vulnerability. The write overwrites the C++ vtable pointer of an adjacent `unc_decoder_component_interleave` object; the next virtual call dispatches to an attacker-chosen address. Version 1.22.0 patches the issue. This vulnerability could allow for code execution, and defenders should review the affected scope and apply the patch or mitigations as necessary.

Vendor
strukturag
Product
libheif
CVSS
MEDIUM 6.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-07-21
Original CVE updated
2026-07-22
Advisory published
2026-07-21
Advisory updated
2026-07-22

Who should care

Users of libheif 1.19.0 through 1.21.2 who process HEIF files from untrusted sources should apply the patch in version 1.22.0 to prevent potential code execution. This is particularly important for operators of systems that handle HEIF files, as the vulnerability could allow for code execution. Security teams and vulnerability management teams should review the affected scope and apply the patch or mitigations as necessary.

Technical summary

The vulnerability is caused by a lack of proper bounds checking in the uncompressed tile decoder of libheif. When processing a specially crafted HEIF file with specific characteristics (uncompressed `unci` codec, tiled, component-interleaved, 4:2:0), an attacker can trigger a heap out-of-bounds write. This write operation overwrites the C++ vtable pointer of an adjacent `unc_decoder_component_interleave` object. As a result, when the program makes the next virtual call, it will dispatch to an attacker-chosen address, potentially allowing for code execution.

Defensive priority

Medium

Recommended defensive actions

  • Apply the patch in version 1.22.0
  • Restrict processing of HEIF files to trusted sources
  • Monitor for updates from the libheif maintainers
  • Review compensating controls for exposed systems while remediation is scheduled and verified
  • Check relevant monitoring, detection, and logs for exposed assets that need extra review
  • Track exceptions, retest remediated assets, and close the item only after evidence is documented
  • Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record was published on 2026-07-21T22:17:12.503Z and was last modified on 2026-07-22T20:38:58.497Z. The NVD entry is currently Awaiting Analysis. There is limited information available about the vulnerability, and defenders should verify the affected scope and severity with the vendor. The CVE record and NVD entry provide the most up-to-date information.

Official resources

AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-07-21T22:17:12.503Z and has not been modified since then. The NVD entry is currently Awaiting Analysis.