---
cve: "CVE-2026-62291"
severity: "MEDIUM"
cvss: 5.3
epss: "0.1%"
vendor: "strukturag"
kev: false
exploited: false
published: "2026-08-18 22:17:02"
tags: [cve, security, medium]
source: tsecurity.de CVE-Dossier
exported: "2026-09-21T14:48:04+02:00"
---

# CVE-2026-62291

> 5.3 MEDIUM · 🧪 PoC

## Beschreibung

libheif is a HEIF and AVIF file format decoder and encoder. In 1.23.0 and earlier, a crafted image sequence with a 2x2 primary plane and a 256x256 auxiliary alpha plane can cause attacker-controlled heap corruption during a normal decode and re-encode workflow. Track_Visual::decode_next_image_sample() calls transfer_channel_from_image_as() without checking that the auxiliary alpha dimensions match the main frame. The resulting inconsistent image reaches heif_track_decode_next_image() and then heif_context_encode_image(). In unc_encoder::encode(), unc_encoder_component_interleave::encode_tile() sizes its buffer with compute_tile_data_size_bytes() using the primary dimensions but copies each component using its actual plane dimensions. The oversized alpha plane is therefore copied beyond the allocation, causing an out-of-bounds write; the inverse size mismatch can also produce an out-of-bounds read. This issue is fixed in version 1.23.1.

## CVSS-Vektor

```
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:L/I:L/A:L
```

| Metrik | Wert | Bewertung |
|---|---|---|
| AV Angriffsvektor | Lokal | good |
| AC Komplexität | Gering | bad |
| PR Privilegien | Keine | bad |
| UI Interaktion | Erforderlich | good |
| S Scope | Unverändert | good |
| C Vertraulichkeit | Gering | warn |
| I Integrität | Gering | warn |
| A Verfügbarkeit | Gering | warn |

## Patch verfügbar (OSV)

- ac5521ad50399885de96bb6a0733a5d2442740f9 (Commit)
- 2c4bbb54c2738d4a5efbbe3e5fa1d5d76bb88eb0 (Commit)

## Referenzen

- <https://github.com/strukturag/libheif/security/advisories/GHSA-xpw3-9rhw-482x>
- <https://github.com/strukturag/libheif/commit/ac5521ad50399885de96bb6a0733a5d2442740f9>
- <https://github.com/strukturag/libheif/releases/tag/v1.23.1>

---
_Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-62291) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_