CVE-2026-32738
Publication date 19 May 2026
Last updated 19 June 2026
Ubuntu priority
Description
libheif is a HEIF and AVIF file format decoder and encoder. In versions 1.21.2 and below, a crafted 792-byte HEIF sequence file with samples_per_chunk=0 in the stsc box causes an unsigned integer underflow in the Chunk constructor (m_last_sample = 0 + 0 - 1 = UINT32_MAX), mapping all samples to an empty chunk and resulting in a denial of service. When any sample is accessed, the library reads from index 0 of an empty std::vector, causing a guaranteed SEGV (null-page read). The file parses successfully without producing an error; the crash occurs on the first frame access. This issue has been fixed in version 1.22.0.
Status
| Package | Ubuntu Release | Status |
|---|---|---|
| libheif | 26.04 LTS resolute |
Fixed 1.21.2-3ubuntu0.1
|
| 25.10 questing |
Fixed 1.20.2-1ubuntu0.4
|
|
| 24.04 LTS noble |
Not affected
|
|
| 22.04 LTS jammy |
Not affected
|
|
| 20.04 LTS focal |
Not affected
|
|
| 18.04 LTS bionic |
Not affected
|
Severity score breakdown
CVSS version: CVSS v3.0
Base score
6.5 · Medium
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
References
Related Ubuntu Security Notices (USN)
- USN-8454-1
- libheif vulnerabilities
- 18 June 2026