CVE-2026-65704
FFmpeg 8.1.2 Out-of-Bounds Write via TY Demuxer and Shorten Decoder
Description
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 demux_audio() function decrements packet size without bounds checking, producing a negative size value that is passed to memcpy() in shorten_decode_frame(), where conversion to size_t wraps the value to near SIZE_MAX and triggers reads beyond the source allocation and writes far beyond the Shorten decoder's bitstream buffer.
INFO
Published Date :
July 23, 2026, 8:17 p.m.
Last Modified :
Aug. 7, 2026, 12:16 a.m.
Remotely Exploit :
No
Source :
[email protected]
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 3.1 | HIGH | [email protected] | ||||
| CVSS 3.1 | HIGH | MITRE-CVE | ||||
| CVSS 4.0 | HIGH | 83251b91-4cc7-4094-a5c7-464a1b83ea10 | ||||
| CVSS 4.0 | HIGH | [email protected] |
Solution
- Update FFmpeg to a patched version.
- Avoid processing untrusted ffconcat files.
- Do not use the -safe 0 flag with untrusted input.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-65704.
| URL | Resource |
|---|---|
| https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/de771bd52774a52d45b0e2c82e56995a1ef40df7 | Patch |
| https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23767 | Issue Tracking Patch |
| https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-write-via-ty-demuxer-and-shorten-decoder | Third Party Advisory |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-65704 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-65704
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-65704 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-65704 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Aug. 07, 2026
Action Type Old Value New Value Added CPE Configuration OR *cpe:2.3:a:ffmpeg:ffmpeg:*:*:*:*:*:*:*:* versions up to (including) 8.1.2 Added Reference Type VulnCheck: https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/de771bd52774a52d45b0e2c82e56995a1ef40df7 Types: Patch Added Reference Type VulnCheck: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23767 Types: Issue Tracking, Patch Added Reference Type VulnCheck: https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-write-via-ty-demuxer-and-shorten-decoder Types: Third Party Advisory -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 24, 2026
Action Type Old Value New Value Changed SSVC {'id': 'CVE-2026-65704', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-23T19:42:41.569092Z'} {'id': 'CVE-2026-65704', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-23T00:00:00+00:00'} -
New CVE Received by [email protected]
Jul. 23, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://code.ffmpeg.org/FFmpeg/FFmpeg', 'vendor': 'FFmpeg', 'product': 'FFmpeg', 'versions': [{'status': 'affected', 'version': '0', 'versionType': 'custom', 'lessThanOrEqual': '8.1.2'}, {'status': 'unaffected', 'version': 'de771bd52774a52d45b0e2c82e56995a1ef40df7', 'versionType': 'git'}], 'defaultStatus': 'affected'}] Added Description 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 demux_audio() function decrements packet size without bounds checking, producing a negative size value that is passed to memcpy() in shorten_decode_frame(), where conversion to size_t wraps the value to near SIZE_MAX and triggers reads beyond the source allocation and writes far beyond the Shorten decoder's bitstream buffer. Added CVSS V4.0 AV:L/AC:L/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X Added CVSS V3.1 AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H Added CWE CWE-787 Added CWE CWE-191 Added Reference https://code.ffmpeg.org/FFmpeg/FFmpeg/commit/de771bd52774a52d45b0e2c82e56995a1ef40df7 Added Reference https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/23767 Added Reference https://www.vulncheck.com/advisories/ffmpeg-out-of-bounds-write-via-ty-demuxer-and-shorten-decoder -
CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 23, 2026
Action Type Old Value New Value Added SSVC {'id': 'CVE-2026-65704', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'no'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-23T19:42:41.569092Z'}