What is CVE-2018-5766?

CVE-2018-5766 is a high-severity vulnerability in Libav, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.8/10. Published 2018-01-18.

How severe is CVE-2018-5766?

High severity. CVSS v3 base score is 8.8 out of 10.

Buffer overflow in Libav

CVE-2018-5766

In Libav through 12.2, there is an invalid memcpy in the av_packet_ref function of libavcodec/avpacket.c. Remote attackers could leverage this vulnerability to cause a denial of service (segmentation fault) via a crafted avi file.

Vulnerability class: Buffer Overflow

Published 2018-01-18 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 8.8 (High). Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.025 (83.9th percentile), scored 2026-09-29.

Low probability of exploitation in the next 30 days, but still tracked. 84th percentile — 83.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.025 · newest: 0.025 · change: 0.000

Affected products

Libav

Weakness classification (CWE)

CWE-119 — Improper Restriction of Operations within the Bounds of a Memory Buffer

References

bugzilla.libav.org/show_bug.cgi (Exploit, Third Party Advisory, Issue Tracking)
www.securityfocus.com/bid/102793 (VDB Entry, Third Party Advisory, vdb-entry)
lists.debian.org/debian-lts-announce/2019/09/msg00000.html (mailing-list)

Frequently asked questions

What is CVE-2018-5766?: CVE-2018-5766 is a high-severity vulnerability in Libav, classified under Improper Restriction of Operations within the Bounds of a Memory Buffer. CVSS score: 8.8/10. Published 2018-01-18.
How severe is CVE-2018-5766?: High severity. CVSS v3 base score is 8.8 out of 10.