libbpf 0.6.0 and 0.6.1 has a heap-based buffer overflow (4 bytes) in __bpf_object__open (called from bpf_object__open_mem and bpf-object-fu…

published 2021-12-31 4 y ago modified 2026-06-17 4 mo ago also BIT-bpftool-2021-45940 , EUVD-2021-32649

cvss: 6.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 1.3%; EPSS 1.3% chance of exploitation in 30 days, percentile 69%
public exploits: 0; none known

libbpf 0.6.0 and 0.6.1 has a heap-based buffer overflow (4 bytes) in __bpf_object__open (called from bpf_object__open_mem and bpf-object-fuzzer.c).

Patch / fix

distros 1

libbpf Debian 14, Debian 13, Debian 12 0.7.0-2

debian advisories DEBIAN-CVE-2021-45940

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-45940 updated 2026-06-26 cvss 4.5

libbpf: heap-based buffer overflow (4 bytes) in __bpf_object__open

Red Hat Enterprise Linux 8 libbpf
affected: no fix planned “Will not fix”
Red Hat Enterprise Linux 9 libbpf
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

1.25% chance of exploitation in the next 30 days, higher than 69% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

github.com https://github.com/google/oss-fuzz-vulns/blob/main/vulns/libbpf/OSV-2021-1562.yaml referenced PoC, tagged "exploit" by a source, unverified
bugs.chromium.org https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=40868 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
OSV	3.1	6.5	CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

Affected packages

ecosystem	package	affected	fixed in
bitnami	bpftool	>=0.6.0, <=0.6.0 >=0.6.1, <=0.6.1	no fix listed

Classification

Weakness

CWE-787 Out-of-bounds Write

References

github.com /google/oss-fuzz-vulns/blob/main/vulns/libbpf/OSV-2021-1562.yaml
exploit, third-party-advisory, web
bugs.chromium.org /p/oss-fuzz/issues/detail?id=40868
exploit, issue-tracking, third-party-advisory, web

Sources

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