What is CVE-2018-13305?

CVE-2018-13305 is a high-severity vulnerability in Ffmpeg, classified under Out-of-bounds Read. CVSS score: 8.1/10. Published 2018-07-05.

How severe is CVE-2018-13305?

High severity. CVSS v3 base score is 8.1 out of 10.

Is CVE-2018-13305 known to be exploited?

2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.

Out-of-bounds Read in Ffmpeg

CVE-2018-13305

In FFmpeg 4.0.1, due to a missing check for negative values of the mquant variable, the vc1_put_blocks_clamped function in libavcodec/vc1_block.c may trigger an out-of-array access while converting a crafted AVI file to MPEG4, leading to an information disclosure or a denial of service.

Vulnerability class: Buffer Overflow

Published 2018-07-05 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.1 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H.

EPSS exploit prediction

EPSS: 0.014 (71.6th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 72nd percentile — 71.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.014 · newest: 0.014 · change: 0.000

Affected products

Ffmpeg — versions 4.0.1

Weakness classification (CWE)

CWE-125 — Out-of-bounds Read

Public proof-of-concept exploits

References

github.com/FFmpeg/FFmpeg/commit/d08d4a8c7387e758d439b0592782e4cfa2b4d6a4 (Patch)
lists.opensuse.org/opensuse-security-announce/2020-01/msg00012.html (vendor-advisory)

Frequently asked questions

What is CVE-2018-13305?: CVE-2018-13305 is a high-severity vulnerability in Ffmpeg, classified under Out-of-bounds Read. CVSS score: 8.1/10. Published 2018-07-05.
How severe is CVE-2018-13305?: High severity. CVSS v3 base score is 8.1 out of 10.
Is CVE-2018-13305 known to be exploited?: 2 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.