Linux: Out-of-bounds Read
CVE-2026-63934 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 90e809376b0f0d1ddec2eec954aecdd2a5b40b0e, 8654b5e2617819ff4f7c78071dfd0275e971a9b6, b64dd5f3b38911054cbcc570df617e3e8e75e562 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 90e809376b0f0d1ddec2eec954aecdd2a5b40b0e or 8654b5e2617819ff4f7c78071dfd0275e971a9b6 or b64dd5f3b38911054cbcc570df617e3e8e75e562 or 31bbd4b87dd6701fa10e03ba7f6268e49e178d16, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.259 or 5.15.210 or 6.1.176 or 6.6.143, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 9dbf091da080508e9f632d307f357beb79a0766b up to, but not including, 90e809376b0f0d1ddec2eec954aecdd2a5b40b0e; 9dbf091da080508e9f632d307f357beb79a0766b up to, but not including, 8654b5e2617819ff4f7c78071dfd0275e971a9b6; 9dbf091da080508e9f632d307f357beb79a0766b up to, but not including, b64dd5f3b38911054cbcc570df617e3e8e75e562; 9dbf091da080508e9f632d307f357beb79a0766b up to, but not including, 31bbd4b87dd6701fa10e03ba7f6268e49e178d16; 9dbf091da080508e9f632d307f357beb79a0766b up to, but not including, 63203bd072b613c18c237b906b1c9d2dc4527337; 9dbf091da080508e9f632d307f357beb79a0766b up to, but not including, 15a0b3f33ffb6c78b3de6f69b026ceb09b973dd1; 9dbf091da080508e9f632d307f357beb79a0766b up to, but not including, cfc3283859cfdeacadf80d5e6880bdf871ffeaa6; 9dbf091da080508e9f632d307f357beb79a0766b up to, but not including, 6bdc3023d62ed5c7d591f0eb27a5adb37fb892ae; and 1 more ranges | 90e809376b0f0d1ddec2eec954aecdd2a5b40b0e, 8654b5e2617819ff4f7c78071dfd0275e971a9b6, b64dd5f3b38911054cbcc570df617e3e8e75e562, 31bbd4b87dd6701fa10e03ba7f6268e49e178d16, 63203bd072b613c18c237b906b1c9d2dc4527337, 15a0b3f33ffb6c78b3de6f69b026ceb09b973dd1 |
| Linux | Linux Kernel | 3.9 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.93; 6.13 up to, but not including, 6.18.35; 6.19 up to, but not including, 7.0.12; 7.1 | 5.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.93, 6.18.35 |
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: iio: gyro: itg3200: fix i2c read into the wrong stack location itg3200_read_all_channels() takes `__be16 *buf' as a parameter and fills the i2c_msg destination as `(char *)&buf'. Since `buf' is the parameter (a pointer), `&buf' is the address of the local pointer slot on the stack of itg3200_read_all_channels(), not the address of the caller's scan buffer. The (char *) cast hides the type mismatch. i2c_transfer() therefore writes ITG3200_SCAN_ELEMENTS * sizeof(s16) = 8 bytes into the parameter's stack slot, which is discarded when the function returns. The caller's scan buffer in itg3200_trigger_handler() is never written to, so iio_push_to_buffers_with_timestamp() pushes uninitialised stack contents to userspace via /dev/iio:deviceX every scan -- both a functional bug (no actual gyroscope or temperature data is delivered through the triggered buffer) and an information leak. The non-buffered read_raw() path is unaffected: it goes through itg3200_read_reg_s16() which uses `&out' on a local s16 value, where that is correct. Drop the spurious `&' so the i2c read writes into the caller's buffer.
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/15a0b3f33ffb6c78b3de6f69b026ceb09b973dd1
- git.kernel.org/stable/c/31bbd4b87dd6701fa10e03ba7f6268e49e178d16
- git.kernel.org/stable/c/63203bd072b613c18c237b906b1c9d2dc4527337
- git.kernel.org/stable/c/6bdc3023d62ed5c7d591f0eb27a5adb37fb892ae
- git.kernel.org/stable/c/8654b5e2617819ff4f7c78071dfd0275e971a9b6
- git.kernel.org/stable/c/90e809376b0f0d1ddec2eec954aecdd2a5b40b0e
- git.kernel.org/stable/c/b64dd5f3b38911054cbcc570df617e3e8e75e562
- git.kernel.org/stable/c/cfc3283859cfdeacadf80d5e6880bdf871ffeaa6
Recent Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.8 High severity
- 7.3 High severity
- 7.1 High severity
- 7.8 High severity
- 9.8 Critical severity
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