Vulnerability Details CVE-2026-45927
In the Linux kernel, the following vulnerability has been resolved:
bpf: Require frozen map for calculating map hash
Currently, bpf_map_get_info_by_fd calculates and caches the hash of the
map regardless of the map's frozen state.
This leads to a TOCTOU bug where userspace can call
BPF_OBJ_GET_INFO_BY_FD to cache the hash and then modify the map
contents before freezing.
Therefore, a trusted loader can be tricked into verifying the stale hash
while loading the modified contents.
Fix this by returning -EPERM if the map is not frozen when the hash is
requested. This ensures the hash is only generated for the final,
immutable state of the map.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 7.0%
CVSS Severity
CVSS v3 Score 4.7
References
Products affected by CVE-2026-45927
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cpe:2.3:o:linux:linux_kernel:6.18
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cpe:2.3:o:linux:linux_kernel:6.18.1
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cpe:2.3:o:linux:linux_kernel:6.18.10
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cpe:2.3:o:linux:linux_kernel:6.18.11
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cpe:2.3:o:linux:linux_kernel:6.18.13
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cpe:2.3:o:linux:linux_kernel:6.18.2
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cpe:2.3:o:linux:linux_kernel:6.18.3
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cpe:2.3:o:linux:linux_kernel:6.18.4
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cpe:2.3:o:linux:linux_kernel:6.18.5
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cpe:2.3:o:linux:linux_kernel:6.18.6
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cpe:2.3:o:linux:linux_kernel:6.18.7
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cpe:2.3:o:linux:linux_kernel:6.18.8
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cpe:2.3:o:linux:linux_kernel:6.18.9
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cpe:2.3:o:linux:linux_kernel:6.19
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cpe:2.3:o:linux:linux_kernel:6.19.1
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cpe:2.3:o:linux:linux_kernel:6.19.3