libde265 v1.0.4 contains a heap buffer overflow in the put_weighted_pred_avg_16_fallback function, which can be exploited via a crafted a f…

published 2021-09-16 5 y ago modified 2026-06-17 4 mo ago also EUVD-2020-14368

cvss: 6.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.4%; EPSS 1.4% chance of exploitation in 30 days, percentile 73%
public exploits: 0; none known

libde265 v1.0.4 contains a heap buffer overflow in the put_weighted_pred_avg_16_fallback function, which can be exploited via a crafted a file.

Patch / fix

distros 4

debian ubuntu alpine arch linux

libde265 Debian 14, Debian 13, Debian 12 1.0.9-1

debian advisories DEBIAN-CVE-2020-21600

libde265 Ubuntu 20.04 LTS 1.0.4-1ubuntu0.1
libde265 Ubuntu Pro 16.04 LTS 1.0.2-2ubuntu0.16.04.1~esm1
libde265 Ubuntu Pro 18.04 LTS 1.0.2-2ubuntu0.18.04.1~esm1

ubuntu advisories UBUNTU-CVE-2020-21600

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

libde265 Alpine 3.24, Alpine 3.23, Alpine 3.22 +8 more 1.0.11-r0

alpine advisories ALPINE-CVE-2020-21600

Alpine secdb © Alpine Linux, from https://secdb.alpinelinux.org via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

libde265 Arch Linux 1.0.10-1

arch linux advisories AVG-2396

Exploit prediction

1.44% chance of exploitation in the next 30 days, higher than 73% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/strukturag/libde265/issues/243 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
NVD	2.0	4.3	AV:N/AC:M/Au:N/C:N/I:N/A:P

Classification

Weakness

CWE-787 Out-of-bounds Write

References

github.com /strukturag/libde265/issues/243
exploit, issue-tracking, third-party-advisory
debian.org /security/2023/dsa-5346
vendor-advisory
cwe.mitre.org /data/definitions/122.html
technical-description

Sources

CVE List CVE-2020-21600
NVD CVE-2020-21600

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary