Vulnerability · Published Sep 18, 2026 · Assigned by GitHub_M
CVE-2026-84446libheif: Sequence decode timing-table initialization allows non-terminating loops and unbounded memory, bypassing max_sequence_frames
High 7.5
In plain English
A high-severity infinite loop in libheif from strukturag. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 40% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
libheif is a HEIF and AVIF file format decoder and encoder. Prior to 1.23.2, crafted HEIF sequence timing and edit-list data can make Track::init_sample_timing_table() compute a logical m_num_output_samples value that exceeds the uint32_t counters used by Track_Visual::decode_next_image_sample() and Track::get_next_sample_raw_data(). The resulting comparison can never reach the oversized output count, causing non-terminating decode or raw-sample loops and bypassing max_sequence_frames. The same sequence path repeatedly calls Box_stts::get_sample_duration() and allocates Chunk::m_sample_ranges and Track::m_presentation_timeline outside MemoryHandle accounting, allowing severe CPU and memory exhaustion from a small file. This issue is fixed in version 1.23.2.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | libheif | no fix listed | DEBIAN-CVE-2026-84446 |
| Debian:13 | libheif | 1.23.4-1~deb13u1 | DEBIAN-CVE-2026-84446 |
| Debian:14 | libheif | 1.23.2-1 | DEBIAN-CVE-2026-84446 |
| Ubuntu:24.04:LTS | libheif | 1.17.6-1ubuntu4.9 | USN-8846-1 |
| Ubuntu:26.04:LTS | libheif | 1.21.2-3ubuntu0.6 | UBUNTU-CVE-2026-84446 |
| Ubuntu:26.04:LTS | libheif | 1.21.2-3ubuntu0.6 | USN-8846-1 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| strukturag | libheif | < 1.23.2 |
Weakness: CWE-835 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H