# CVE-2026-62289 — strukturag libheif

> As of 2026-08-19, CVE-2026-62289 is a MEDIUM-severity vulnerability in strukturag libheif, CVSS v3.1 4.3, EPSS 0.3% (32.8th percentile). No Threadlinqs-tracked threat campaign has been attributed to CVE-2026-62289 as of 2026-08-19; the identifier is re-checked against the Threadlinqs threat corpus on every daily ingest.

**Last updated:** 2026-08-19

## What is CVE-2026-62289?

libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.0 and earlier, a crafted HEIF or AVIF file containing a clean aperture box can reduce an image dimension to zero and crash or corrupt tiling results when heif_image_handle_get_image_tiling(handle, 1, &tiling) is called. ImageItem::get_heif_image_tiling() returns already transformed dimensions, and process_image_transformations_on_tiling() applies the clean aperture transformation again. The second application passes zero to Box_clap::left_rounded(0), where image_width minus one underflows and constructs Fraction(0xFFFFFFFF, 2). Debug builds reach an assertion and abort, while release builds can return a corrupt crop and zero-width tiling result. The affected implementation spans libheif/image-items/image_item.cc, libheif/context.cc, and libheif/box.cc. This issue is fixed in version 1.23.1.

The record classifies CVE-2026-62289 under weakness classes [CWE-191](https://cwe.mitre.org/data/definitions/191.html), [CWE-617](https://intel.threadlinqs.com/cwe/CWE-617). Its CVSS v3 base vector states that the flaw is reachable remotely over the network, needs no prior authentication, needs a user to take an action first. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 48 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 4.3 — MEDIUM (`CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:L`)
- **EPSS (FIRST):** 0.3% probability of exploitation in the next 30 days, higher than 32.8% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 3.5/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-08-18, last modified 2026-08-19

## Is CVE-2026-62289 being exploited?

It currently carries a trending score of 38 in the Threadlinqs vulnerability feed.

## Affected products and versions

- **strukturag**: libheif

## How to fix CVE-2026-62289

No vendor patch reference has been recorded for CVE-2026-62289 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-62289

No threat campaign in the Threadlinqs corpus currently references CVE-2026-62289, in its CVE list or as an indicator. The linkage is recomputed from the live corpus on every daily ingest, so this section fills in as soon as a tracked campaign cites the identifier.

## Sources

Enriched from CVE.org, NVD, FIRST EPSS. Last verified by Threadlinqs on 2026-08-19. This product uses the NVD API but is not endorsed or certified by the NVD.

**Vendor advisory and patch**

- [github.com](https://github.com/strukturag/libheif/security/advisories/GHSA-jc8f-p23p-5hjg)

**Other references**

- [github.com](https://github.com/strukturag/libheif/commit/f01870c1d7323a3003796d58eba7fff502be994c)
- [github.com (v1.23)](https://github.com/strukturag/libheif/releases/tag/v1.23.1)

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-62289
Full detection coverage and IOCs for threats exploiting CVE-2026-62289 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp