libheif: `clap` + oversized `ispe` aborts on an assert in `Fraction::Fraction` (incomplete fix for CVE-2026-62289)
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · Low
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-617.
Summary
libheif is a HEIF and AVIF file format decoder and encoder. From 1.19.0 until 1.23.3, a crafted image item containing a clap property and an ispe width or height greater than INT32_MAX + 1 can reach crop calculations through heif_image_handle_get_image_tiling(). Box_clap::left_rounded() or Box_clap::top_rounded() passes the image dimension minus one to Fraction::Fraction(), whose uint32_t constructor uses an assertion as input validation, causing assert-enabled builds to abort. Release builds can instead compute invalid crop geometry, and the tiling API returns dimensions that the normal decode security limits reject. This issue is fixed in version 1.23.3.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| strukturag | libheif | 1.19.0 to before 1.23.3 | 1.23.3 | Patch available | CNA |
- libheif Vendorstrukturag Affected 1.19.0 to before 1.23.3 Fixed in 1.23.3 Patch available CNA
CPE names Threatist (inferred) · 1
Inferred from how NVD named this product before; not given by a source.
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:struktur:libheif:*:*:*:*:*:*:*:* | — | — | strukturag |
- cpe:2.3:a:struktur:libheif:*:*:*:*:*:*:*:* Versions — — ·strukturag
Remediation
- Fix · CNA libheif (strukturag) Fixed in 1.23.3
Vendor assessments
Timeline
- 2026-10-02 Threatist record created from CVE-2026-84450
References
More strukturag vulnerabilities
- TI-2026-57994 libheif: Heap buffer overflow in `scale_nearest_neighbor()` via duplicate Alpha planes from nested `iden`/`auxl` items CVSS 3.1CRITICAL 9.8
- TI-2026-25594 NULL Pointer Dereference in libde265 CVSS 4.0HIGH 8.7
- TI-2023-27026 Libde265 v1.0.14 was discovered to contain a global buffer overflow vulnerability in the… CVSS 3.1HIGH 8.8
- TI-2023-27020 libheif v1.17.5 was discovered to contain a segmentation violation via the function… CVSS 3.1HIGH 8.8
- TI-2026-58037 Resource allocation without limits in strukturag libheif CVSS 3.1HIGH 7.5
- TI-2026-57995 libheif: brotli/zlib decompression paths lack output-size limits, allowing decompression-bomb OOM/DoS CVSS 3.1HIGH 7.5
Sources
- CVE-2026-84450 · CVE Program
- CVE-2026-84450 · NVD
- FIRST EPSS
- CVE-2026-84450 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences