CVE-2026-45927
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
27/05/2026
Last modified:
25/06/2026
Description
In the Linux kernel, the following vulnerability has been resolved:<br />
<br />
bpf: Require frozen map for calculating map hash<br />
<br />
Currently, bpf_map_get_info_by_fd calculates and caches the hash of the<br />
map regardless of the map&#39;s frozen state.<br />
<br />
This leads to a TOCTOU bug where userspace can call<br />
BPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map<br />
contents before freezing.<br />
<br />
Therefore, a trusted loader can be tricked into verifying the stale hash<br />
while loading the modified contents.<br />
<br />
Fix this by returning -EPERM if the map is not frozen when the hash is<br />
requested. This ensures the hash is only generated for the final,<br />
immutable state of the map.
Impact
Base Score 3.x
4.70
Severity 3.x
MEDIUM
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.18 (including) | 6.18.14 (excluding) |
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 6.19 (including) | 6.19.4 (excluding) |
To consult the complete list of CPE names with products and versions, see this page