CVE-2026-23235
What it is
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix out-of-bounds access in sysfs attribute read/write Some f2fs sysfs attributes suffer from out-of-bounds memory access and incorrect handling of integer values whose size is not 4 bytes. For example: vm:~# echo 65537 > /sys/fs/f2fs/vde/carve_out vm:~# cat /sys/fs/f2fs/vde/carve_out 65537 vm:~# echo 4294967297 > /sys/fs/f2fs/vde/atgc_age_threshold vm:~# cat /sys/fs/f2fs/vde/atgc_age_threshold 1 carve_out maps to {struct f2fs_sb_info}->carve_out, which is a 8-bit integer. However, the sysfs interface allows setting it to a value larger than 255, resulting in an out-of-range update. atgc_age_threshold maps to {struct atgc_management}->age_threshold, which is a 64-bit integer, but its sysfs interface cannot correctly set values larger than UINT_MAX. The root causes are: 1. __sbi_store() treats all default values as unsigned int, which prevents updating integers larger than 4 bytes and causes out-of-bounds writes for integers smaller than 4 bytes. 2. f2fs_sbi_show() also assumes all default values are unsigned int, leading to out-of-bounds reads and incorrect access to integers larger than 4 bytes. This patch introduces {struct f2fs_attr}->size to record the actual size of the integer associated with each sysfs attribute. With this information, sysfs read and write operations can correctly access and update values according to their real data size, avoiding memory corruption and truncation.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.1 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Analyzed
Affected
- Linux Kernel < 5.10.251
- Linux Kernel < 5.15.201
- Linux Kernel < 6.1.164
- Linux Kernel < 6.6.127
- Linux Kernel < 6.12.74
- Linux Kernel < 6.18.13
- Linux Kernel < 6.19.3
Attack profile CVSS 3.1 · 7.1
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2026-23235.md and follow it. Check whether this project is affected by CVE-2026-23235. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/3a905e183c047577b154f08a78ac3039e9454703
- https://git.kernel.org/stable/c/438a405fbad6882df0e34b3e1a16839a71f04240
- https://git.kernel.org/stable/c/4ef30b9f1641c9e877792df6b049f1cf507d002d
- https://git.kernel.org/stable/c/6a6c07a9b49e43f0df42d7118fc76aa555c73d98
- https://git.kernel.org/stable/c/98ea0039dbfdd00e5cc1b9a8afa40434476c0955
- https://git.kernel.org/stable/c/d4a594dd952df123cbdcdee9b9640d9d55e4a954
- https://git.kernel.org/stable/c/e85a99db9ab85dfc30d93b0ca0e9156f3127f55a
- https://git.kernel.org/stable/c/eebd72cff518ac87e660aefb8a41224bd88c32ce
References
- https://git.kernel.org/stable/c/3a905e183c047577b154f08a78ac3039e9454703
- https://git.kernel.org/stable/c/438a405fbad6882df0e34b3e1a16839a71f04240
- https://git.kernel.org/stable/c/4ef30b9f1641c9e877792df6b049f1cf507d002d
- https://git.kernel.org/stable/c/6a6c07a9b49e43f0df42d7118fc76aa555c73d98
- https://git.kernel.org/stable/c/98ea0039dbfdd00e5cc1b9a8afa40434476c0955
- https://git.kernel.org/stable/c/d4a594dd952df123cbdcdee9b9640d9d55e4a954
- https://git.kernel.org/stable/c/e85a99db9ab85dfc30d93b0ca0e9156f3127f55a
- https://git.kernel.org/stable/c/eebd72cff518ac87e660aefb8a41224bd88c32ce