FFmpeg through 8.1.2 contains an out-of-bounds write vulnerability that allows attackers to cause heap corruption by supplying a crafted ffconcat file processed with the -safe 0 flag. The TY demuxer's demuxaudio() function decrements packet size without bounds checking, producing a negative size value that is passed to memcpy() in shortendecodeframe(), where conversion to sizet wraps the value to near SIZE_MAX and triggers reads beyond the source allocation and writes far beyond the Shorten decoder's bitstream buffer.
{
"cwe_ids": [
"CWE-191",
"CWE-787"
],
"cna_assigner": "VulnCheck",
"unresolved_ranges": [
{
"source": "AFFECTED_FIELD",
"extracted_events": [
{
"last_affected": "8.1.2"
}
]
},
{
"source": "CPE_FIELD",
"extracted_events": [
{
"last_affected": "8.1.2"
}
]
},
{
"source": "DESCRIPTION",
"extracted_events": [
{
"fixed": "8.1.2"
}
]
}
],
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/65xxx/CVE-2026-65704.json"
}{
"source": "CPE_RANGE",
"cpe": "cpe:2.3:a:ffmpeg:ffmpeg:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "0"
},
{
"last_affected": "8.1.2"
}
]
}{
"source": "CPE_RANGE",
"cpe": "cpe:2.3:a:ffmpeg:ffmpeg:*:*:*:*:*:*:*:*",
"extracted_events": [
{
"introduced": "0"
},
{
"last_affected": "8.1.2"
}
]
}