FFmpeg before commit acf5d7c contains a heap buffer overflow in the hvcC box writer. When writing an HEVC configuration record with more NAL units of a single type than the count field can represent, the NAL unit count overflows, causing a heap buffer overflow. A crafted HEVC input file triggers the overflow during muxing.
{
"cna_assigner": "VulnCheck",
"cwe_ids": [
"CWE-122"
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/75xxx/CVE-2026-75141.json"
}"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-75141.json"
[
{
"deprecated": false,
"digest": {
"line_hashes": [
"171120489460269271572944630595405024716",
"228269754873946655632573446782989375232",
"147548849313941577437332154418106305823"
],
"threshold": 0.9
},
"id": "CVE-2026-75141-521eb75b",
"signature_type": "Line",
"signature_version": "v1",
"source": "https://code.ffmpeg.org/FFmpeg/FFmpeg@acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781",
"target": {
"file": "libavformat/hevc.c"
}
},
{
"deprecated": false,
"digest": {
"function_hash": "300450159533624974693068667980417737242",
"length": 350
},
"id": "CVE-2026-75141-9059cfe7",
"signature_type": "Function",
"signature_version": "v1",
"source": "https://code.ffmpeg.org/FFmpeg/FFmpeg@acf5d7cdc1f9ae8752c23e1ea8d7f355ed780781",
"target": {
"file": "libavformat/hevc.c",
"function": "hvcc_array_add_nal_unit"
}
}
]
"2026-09-30T08:42:36Z"