CyberSecBulletin
CVE-2026-46294NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-46294 is a high-severity out-of-bounds write 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 c8c5311237448f6ffeecc9aec2362e3692623668, 448ee8fb79c26a26599ffa4b2adeb4322d3d3d8c, 526ff9126a0ae087b65726e1faf31114c718020d 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.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to c8c5311237448f6ffeecc9aec2362e3692623668 or 448ee8fb79c26a26599ffa4b2adeb4322d3d3d8c or 526ff9126a0ae087b65726e1faf31114c718020d or f0b0b09d9840838ae77ccdd6a62de0daef4e6e0a, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.140, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, c8c5311237448f6ffeecc9aec2362e3692623668; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 448ee8fb79c26a26599ffa4b2adeb4322d3d3d8c; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 526ff9126a0ae087b65726e1faf31114c718020d; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, f0b0b09d9840838ae77ccdd6a62de0daef4e6e0a; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, d271631023cbe1cbe7c31a0275ab797883be6e0a; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 5af6a879e915ae7bcd83695c316ebb32e1c61bc2; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 8daa6c708ef524089ae43f2aed9190acb26d7df8; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 2fa49cc884f6496a915c35621ba4da35649bf159; and 1 more rangesc8c5311237448f6ffeecc9aec2362e3692623668, 448ee8fb79c26a26599ffa4b2adeb4322d3d3d8c, 526ff9126a0ae087b65726e1faf31114c718020d, f0b0b09d9840838ae77ccdd6a62de0daef4e6e0a, d271631023cbe1cbe7c31a0275ab797883be6e0a, 5af6a879e915ae7bcd83695c316ebb32e1c61bc2
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel2.6.12.1 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.140; 6.7 up to, but not including, 6.12.88; 6.13 up to, but not including, 6.18.30; 6.19 up to, but not including, 7.0.7; 2.6.125.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.88, 6.18.30

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: dm: fix a buffer overflow in ioctl processing Tony Asleson (using Claude) found a buffer overflow in dm-ioctl in the function retrieve_status: 1. The code in retrieve_status checks that the output string fits into the output buffer and writes the output string there 2. Then, the code aligns the "outptr" variable to the next 8-byte boundary: outptr = align_ptr(outptr); 3. The alignment doesn't check overflow, so outptr could point past the buffer end 4. The "for" loop is iterated again, it executes: remaining = len - (outptr - outbuf); 5. If "outptr" points past "outbuf + len", the arithmetics wraps around and the variable "remaining" contains unusually high number 6. With "remaining" being high, the code writes more data past the end of the buffer Luckily, this bug has no security implications because: 1. Only root can issue device mapper ioctls 2. The commonly used libraries that communicate with device mapper (libdevmapper and devicemapper-rs) use buffer size that is aligned to 8 bytes - thus, "outptr = align_ptr(outptr)" can't overshoot the input buffer and the bug can't happen accidentally

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Out-of-bounds Write

The product writes data past the end, or before the beginning, of the intended buffer.

How developers prevent this class of flaw

  • Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer. Be wary that a language's interface to native code may still be subject to overflows, even if the language itself is theoretically safe.
  • Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. Examples include the Safe C String Library (SafeStr) by Messier and Viega, and the Strsafe.h library from Microsoft. These libraries provide safer versions of overflow-prone string-handling functions.
  • Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.

More Out-of-bounds Write vulnerabilities (CWE-787)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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