Linux: Out-of-bounds Read
CVE-2026-43380 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 a0fc1b9c738fba231f190ab960c83202722efee5, c59090c50f62a17129fc4c5407bc4071305a9e82, 52db5ef163c96f916d424e472fb17aadc35a9f7a 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 0.14% 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 a0fc1b9c738fba231f190ab960c83202722efee5 or c59090c50f62a17129fc4c5407bc4071305a9e82 or 52db5ef163c96f916d424e472fb17aadc35a9f7a or b48a0f8d4541a4f6651dc9a64430ce9fdf5c120b, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.203 or 6.1.167 or 6.6.130 or 6.12.78, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | d014538aa38561cd24c5eb228223585f26c5ec71 up to, but not including, a0fc1b9c738fba231f190ab960c83202722efee5; d014538aa38561cd24c5eb228223585f26c5ec71 up to, but not including, c59090c50f62a17129fc4c5407bc4071305a9e82; d014538aa38561cd24c5eb228223585f26c5ec71 up to, but not including, 52db5ef163c96f916d424e472fb17aadc35a9f7a; d014538aa38561cd24c5eb228223585f26c5ec71 up to, but not including, b48a0f8d4541a4f6651dc9a64430ce9fdf5c120b; d014538aa38561cd24c5eb228223585f26c5ec71 up to, but not including, 73a7a345816946d276ad2c46c8bb771de67cfc46; d014538aa38561cd24c5eb228223585f26c5ec71 up to, but not including, 24a7b9daa103fa963b3fd37d8805b23e01621976; d014538aa38561cd24c5eb228223585f26c5ec71 up to, but not including, 25dd70a03b1f5f3aa71e1a5091ecd9cd2a13ee43; 5.11 | a0fc1b9c738fba231f190ab960c83202722efee5, c59090c50f62a17129fc4c5407bc4071305a9e82, 52db5ef163c96f916d424e472fb17aadc35a9f7a, b48a0f8d4541a4f6651dc9a64430ce9fdf5c120b, 73a7a345816946d276ad2c46c8bb771de67cfc46, 24a7b9daa103fa963b3fd37d8805b23e01621976 |
| Linux | Linux Kernel | 5.11 up to, but not including, 5.15.203; 5.16 up to, but not including, 6.1.167; 6.2 up to, but not including, 6.6.130; 6.7 up to, but not including, 6.12.78; 6.13 up to, but not including, 6.18.19; 6.19 up to, but not including, 6.19.9; 7.0 | 5.15.203, 6.1.167, 6.6.130, 6.12.78, 6.18.19, 6.19.9 |
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.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.1 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: hwmon: (pmbus/q54sj108a2) fix stack overflow in debugfs read The q54sj108a2_debugfs_read function suffers from a stack buffer overflow due to incorrect arguments passed to bin2hex(). The function currently passes 'data' as the destination and 'data_char' as the source. Because bin2hex() converts each input byte into two hex characters, a 32-byte block read results in 64 bytes of output. Since 'data' is only 34 bytes (I2C_SMBUS_BLOCK_MAX + 2), this writes 30 bytes past the end of the buffer onto the stack. Additionally, the arguments were swapped: it was reading from the zero-initialized 'data_char' and writing to 'data', resulting in all-zero output regardless of the actual I2C read. Fix this by: 1. Expanding 'data_char' to 66 bytes to safely hold the hex output. 2. Correcting the bin2hex() argument order and using the actual read count. 3. Using a pointer to select the correct output buffer for the final simple_read_from_buffer call.
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
- git.kernel.org/stable/c/24a7b9daa103fa963b3fd37d8805b23e01621976
- git.kernel.org/stable/c/25dd70a03b1f5f3aa71e1a5091ecd9cd2a13ee43
- git.kernel.org/stable/c/52db5ef163c96f916d424e472fb17aadc35a9f7a
- git.kernel.org/stable/c/73a7a345816946d276ad2c46c8bb771de67cfc46
- git.kernel.org/stable/c/a0fc1b9c738fba231f190ab960c83202722efee5
- git.kernel.org/stable/c/b48a0f8d4541a4f6651dc9a64430ce9fdf5c120b
- git.kernel.org/stable/c/c59090c50f62a17129fc4c5407bc4071305a9e82
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 8.2 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 9.1 Critical severity
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