CVE-2026-125267 PUBLISHED

FFmpeg before 8.1.3 and 9.x before 9.0.2 Heap Out-of-Bounds Write via APAC Decoder

Assigner: VulnCheck
Reserved: 09.11.2026 Published: 09.11.2026 Updated: 09.11.2026

FFmpeg before 8.1.3 and 9.x before 9.0.2 contains a heap out-of-bounds write vulnerability in the APAC decoder in libavcodec/apac.c caused by an unreset bitstream index. Attackers can supply a crafted APAC file whose growing bitstream_index triggers an integer overflow, bypassing the reallocation check so memcpy() corrupts heap memory or crashes the application.

CVSS Vector: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CVSS Score: 8.5

Exploitability Metrics		Vulnerable System Impact Metrics		Subsequent System Impact Metrics
Attack Vector	Local	Confidentiality	High	Confidentiality	None
Attack Complexity	Low	Integrity	High	Integrity	None
Attack Requirements	None	Availability	High	Availability	None
Privileges Required	None
User Interaction	Passive

CVSS 4.0

CVSS Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
CVSS Score: 7.8

Attack Vector	Local	Scope	Unchanged
Attack Complexity	Low	Confidentiality Impact	High
Privileges Required	None	Integrity Impact	High
User Interaction	Required	Availability Impact	High

CVSS 3.1

Product Status

Vendor	FFmpeg
Product	FFmpeg
Versions	Default: unaffected affected from 0 to 8.1.3 (excl.) affected from 9.0 to 9.0.2 (excl.)

CVE-2026-125267 PUBLISHED

FFmpeg before 8.1.3 and 9.x before 9.0.2 Heap Out-of-Bounds Write via APAC Decoder

Metrics

Product Status

Credits

References

Problem Types