Linux: Out-of-bounds Read
CVE-2026-45903 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 fdfe75161f6e8c41a7d3023fbb815b537107b806, aa319592892068bd960c1a1c07bd621085b0c63d, 802eef5afb1865bc5536a5302c068ba2215a1f72 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 0.16% 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 fdfe75161f6e8c41a7d3023fbb815b537107b806 or aa319592892068bd960c1a1c07bd621085b0c63d or 802eef5afb1865bc5536a5302c068ba2215a1f72, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.18.14 or 6.19.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 37cce22dbd51a3ef7f6c08c3fb5f1c5075a17fbb up to, but not including, fdfe75161f6e8c41a7d3023fbb815b537107b806; 37cce22dbd51a3ef7f6c08c3fb5f1c5075a17fbb up to, but not including, aa319592892068bd960c1a1c07bd621085b0c63d; 37cce22dbd51a3ef7f6c08c3fb5f1c5075a17fbb up to, but not including, 802eef5afb1865bc5536a5302c068ba2215a1f72; 6.14 | fdfe75161f6e8c41a7d3023fbb815b537107b806, aa319592892068bd960c1a1c07bd621085b0c63d, 802eef5afb1865bc5536a5302c068ba2215a1f72 |
| Linux | Linux Kernel | 6.14 up to, but not including, 6.18.14; 6.19 up to, but not including, 6.19.4 | 6.18.14, 6.19.4 |
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix memory access flags in helper prototypes After commit 37cce22dbd51 ("bpf: verifier: Refactor helper access type tracking"), the verifier started relying on the access type flags in helper function prototypes to perform memory access optimizations. Currently, several helper functions utilizing ARG_PTR_TO_MEM lack the corresponding MEM_RDONLY or MEM_WRITE flags. This omission causes the verifier to incorrectly assume that the buffer contents are unchanged across the helper call. Consequently, the verifier may optimize away subsequent reads based on this wrong assumption, leading to correctness issues. For bpf_get_stack_proto_raw_tp, the original MEM_RDONLY was incorrect since the helper writes to the buffer. Change it to ARG_PTR_TO_UNINIT_MEM which correctly indicates write access to potentially uninitialized memory. Similar issues were recently addressed for specific helpers in commit ac44dcc788b9 ("bpf: Fix verifier assumptions of bpf_d_path's output buffer") and commit 2eb7648558a7 ("bpf: Specify access type of bpf_sysctl_get_name args"). Fix these prototypes by adding the correct memory access flags.
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
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 8.2 High severity
- 7.1 High severity
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