Linux: Out-of-bounds Read
CVE-2026-98149 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions c16c62c91e5d6737a9fbb0a541b8b34610470a2b, 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7 as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.12% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to c16c62c91e5d6737a9fbb0a541b8b34610470a2b or 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7, whichever matches your release line, or a later version.
- Update Linux Kernel to 7.2.7 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360 up to, but not including, c16c62c91e5d6737a9fbb0a541b8b34610470a2b; 8eb76cb03f0f6c2bd7b15cf45dcffcd6bd07a360 up to, but not including, 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7; 7.0 | c16c62c91e5d6737a9fbb0a541b8b34610470a2b, 75b0a6db4300e4c2c9e97a0848deaa7acfb42fb7 |
| Linux | Linux Kernel | 7.0 up to, but not including, 7.2.7; 7.3 | 7.2.7 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix percpu map update indexing with sparse CPU IDs Per-CPU array, hash, and cgroup storage map updates without BPF_F_CPU or BPF_F_ALL_CPUS use a value buffer whose per-CPU slots are packed in possible-CPU order. The buffer is sized as: round_up(value_size, 8) * num_possible_cpus() The update paths iterate over possible CPUs, but use the logical CPU ID to calculate the source offset: value + size * cpu This only works when possible CPU IDs are contiguous starting at zero. For example, with a possible CPU mask of 0,2-3, the buffer contains three slots corresponding to CPUs 0, 2, and 3. CPU2 is therefore expected to use slot 1 and CPU3 slot 2. Instead, the current code uses slots 2 and 3 respectively, causing incorrect per-CPU values and an out-of-bounds read from the update buffer for CPU3. The corresponding lookup paths already use a dense offset while iterating over possible CPUs. Do the same for the array, hash, and cgroup storage update paths, advancing the source offset once for each possible CPU. BPF_F_ALL_CPUS continues to use the same value for every CPU.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Out-of-bounds Read vulnerabilities
- 8.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
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