Buffer overflow in Ffmpeg

CVE-2026-65705

FFmpeg versions 3.4 through 8.1.2 contain an out-of-bounds write vulnerability in the vf_floodfill video filter that allows attackers to corrupt heap memory by supplying a dynamically sized video stream with filtergraph reinitialization disabled via -reinit_filter 0. When config_input() allocates the points traversal stack based on initial frame dimensions and a subsequent larger frame is processed, filter_frame() performs flood-fill neighbor pushes beyond the original allocation boundary, resulting in heap corruption and process crash with potential for code execution depending on heap layout and process hardening.

EPSS: 0.002 (8.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

  • Ffmpeg — versions 3.4, f186c50cf53aec20e9a29059cb22ca3f2d59201c

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-65705?
CVE-2026-65705 is a high-severity vulnerability in Ffmpeg, classified under Incorrect Calculation of Buffer Size. CVSS score: 7.8/10. Published 2026-07-23.
How severe is CVE-2026-65705?
High severity. CVSS v3 base score is 7.8 out of 10.