6.8
MEDIUM CVSS 4.0
CVE-2026-125187
FFmpeg through 9.0.2 TTA Encoder Reachable Assertion via tta_encode_frame()
Description

FFmpeg through 9.0.2 contains a reachable assertion vulnerability in the TTA encoder's tta_encode_frame() in libavcodec/ttaenc.c, which never reserves output packet space for the 4-byte CRC. Attackers can supply audio whose sample values and length produce a small, poorly compressible final frame, triggering the av_assert0() in flush_put_bits() and aborting applications transcoding to TTA.

INFO

Published Date :

Nov. 9, 2026, 7:16 p.m.

Last Modified :

Nov. 9, 2026, 7:16 p.m.

Remotely Exploit :

No
Affected Products

The following products are affected by CVE-2026-125187 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Ffmpeg ffmpeg
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 3.1 MEDIUM [email protected]
CVSS 4.0 MEDIUM 83251b91-4cc7-4094-a5c7-464a1b83ea10
CVSS 4.0 MEDIUM [email protected]
Solution
Update FFmpeg to a version that corrects the TTA encoder assertion vulnerability.
  • Update FFmpeg to a non-vulnerable version.
  • Avoid transcoding to TTA format if possible.
  • Apply vendor patches when available.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-125187 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-2026-125187 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-2026-125187 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2026-125187 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.

  • New CVE Received by [email protected]

    Nov. 09, 2026

    Action Type Old Value New Value
    Added Description FFmpeg through 9.0.2 contains a reachable assertion vulnerability in the TTA encoder's tta_encode_frame() in libavcodec/ttaenc.c, which never reserves output packet space for the 4-byte CRC. Attackers can supply audio whose sample values and length produce a small, poorly compressible final frame, triggering the av_assert0() in flush_put_bits() and aborting applications transcoding to TTA.
    Added CVSS V4.0 AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/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:N/I:N/A:H
    Added CWE CWE-617
    Added Affected New affected value received. <a href="https://github.com/CVEProject/cvelistV5/blob/main/cves/2026/125xxx/CVE-2026-125187.json">CVE-2026-125187</a>
    Added Reference https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/25694
    Added Reference https://github.com/FFmpeg/FFmpeg
    Added Reference https://github.com/FFmpeg/FFmpeg/blob/n9.0.2/libavcodec/ttaenc.c#L93
    Added Reference https://github.com/FFmpeg/FFmpeg/commit/29a629e788c4343ff2e923095b8f38769fe2e470
    Added Reference https://www.vulncheck.com/advisories/ffmpeg-through-9.0.2-tta-encoder-reachable-assertion-via-tta-encode-frame
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.