CVE-2026-74364

bpf: Reject exclusive maps as inner maps in map-in-map

Published Aug 15, 2026 CVSS 3.1 · 7.1 High EPSS < 1% KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:

bpf: Reject exclusive maps as inner maps in map-in-map

An exclusive map (created with excl_prog_hash) is bound to a single
program by hash: check_map_prog_compatibility() refuses to load any
program whose digest does not match map->excl_prog_sha. That check
only runs for maps a program references directly, i.e. its used_maps.
A map reached at runtime through a map-of-maps is never in used_maps,
and bpf_map_meta_equal() does not consider excl_prog_sha, so an
exclusive map can be inserted into a non-exclusive outer map and
then looked up and mutated by an unrelated program, bypassing the
exclusivity guarantee.

For the signed loader this defeats the metadata map exclusivity check
added in the signed loader: the cached map->sha[] is validated against
the signed hash while another program on a hostile host rewrites the
frozen map's contents through the outer map.

Remediation

No solution or workaround provided in the CVE record

Tracking

Sign in to view the affected projects.

Advisories

Source ID Title
Ubuntu USN Ubuntu USN USN-8887-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8889-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-2 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-8888-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-8887-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-9003-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-9043-1 Linux kernel (NVIDIA) vulnerabilities
History
Type Values Removed Values Added
Weaknesses CWE-285
CWE-398
Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N'}

Type Values Removed Values Added
Weaknesses CWE-285
CWE-398
Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: bpf: Reject exclusive maps as inner maps in map-in-map An exclusive map (created with excl_prog_hash) is bound to a single program by hash: check_map_prog_compatibility() refuses to load any program whose digest does not match map->excl_prog_sha. That check only runs for maps a program references directly, i.e. its used_maps. A map reached at runtime through a map-of-maps is never in used_maps, and bpf_map_meta_equal() does not consider excl_prog_sha, so an exclusive map can be inserted into a non-exclusive outer map and then looked up and mutated by an unrelated program, bypassing the exclusivity guarantee. For the signed loader this defeats the metadata map exclusivity check added in the signed loader: the cached map->sha[] is validated against the signed hash while another program on a hostile host rewrites the frozen map's contents through the outer map.
Title bpf: Reject exclusive maps as inner maps in map-in-map
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References
Weaknesses

Sources

Status
PUBLISHED
Assigner
Linux
Published
Updated
Aug 17, 2026, 5:46 AM
Reserved
Aug 15, 2026, 5:44 AM
Status
Received
Published
Aug 15, 2026, 6:22 AM
Modified
Aug 17, 2026, 6:19 AM
Severity
Moderate
Public date
Aug 15, 2026, 12:00 AM