CyberSecBulletin
CVE-2026-23208NVD status: Modified

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-23208 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 480a1490c595a242f27493a4544b3efb21b29f6a, ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41, 282aba56713bbc58155716b55ca7222b2d9cf3c8 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 0.18% 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 480a1490c595a242f27493a4544b3efb21b29f6a or ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41 or 282aba56713bbc58155716b55ca7222b2d9cf3c8 or c4dc012b027c9eb101583011089dea14d744e314, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 4.14.188 or 4.19.132 or 5.4.51 or 5.7.8, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux02c56650f3c118d3752122996d96173d26bb13aa up to, but not including, 480a1490c595a242f27493a4544b3efb21b29f6a; 5ef30e443e6d3654cccecec99cf481a69a0a6d3b up to, but not including, ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41; 99703c921864a318e3e8aae74fde071b1ff35bea up to, but not including, 282aba56713bbc58155716b55ca7222b2d9cf3c8; 2d50acd7dbd0682a56968ad9551341d7fc5b6eaf up to, but not including, c4dc012b027c9eb101583011089dea14d744e314; aba41867dd66939d336fdf604e4d73b805d8039f up to, but not including, e0ed5a36fb3ab9e7b9ee45cd17f09f6d5f594360; d288dc74f8cf95cb7ae0aaf245b7128627a49bf3 up to, but not including, d67dde02049e632ba58d3c44a164a74b6a737154; f0bd62b64016508938df9babe47f65c2c727d25c up to, but not including, 581821f4b2ecbf411027b0af82b561ee208f4ba4; f0bd62b64016508938df9babe47f65c2c727d25c up to, but not including, 152fc4f7b4a8af1c0418d2722f3b2729799cc837; and 10 more ranges480a1490c595a242f27493a4544b3efb21b29f6a, ab0b5e92fc36ee82c1bd01fe896d0f775ed5de41, 282aba56713bbc58155716b55ca7222b2d9cf3c8, c4dc012b027c9eb101583011089dea14d744e314, e0ed5a36fb3ab9e7b9ee45cd17f09f6d5f594360, d67dde02049e632ba58d3c44a164a74b6a737154
LinuxLinux Kernel4.14.186 up to, but not including, 4.14.188; 4.19.130 up to, but not including, 4.19.132; 5.4.49 up to, but not including, 5.4.51; 5.7.6 up to, but not including, 5.7.8; 5.8 up to, but not including, 6.18.10; 4.4.229; 4.9.229; 6.194.14.188, 4.19.132, 5.4.51, 5.7.8, 6.18.10

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: ALSA: usb-audio: Prevent excessive number of frames In this case, the user constructed the parameters with maxpacksize 40 for rate 22050 / pps 1000, and packsize[0] 22 packsize[1] 23. The buffer size for each data URB is maxpacksize * packets, which in this example is 40 * 6 = 240; When the user performs a write operation to send audio data into the ALSA PCM playback stream, the calculated number of frames is packsize[0] * packets = 264, which exceeds the allocated URB buffer size, triggering the out-of-bounds (OOB) issue reported by syzbot [1]. Added a check for the number of single data URB frames when calculating the number of frames to prevent [1]. [1] BUG: KASAN: slab-out-of-bounds in copy_to_urb+0x261/0x460 sound/usb/pcm.c:1487 Write of size 264 at addr ffff88804337e800 by task syz.0.17/5506 Call Trace: copy_to_urb+0x261/0x460 sound/usb/pcm.c:1487 prepare_playback_urb+0x953/0x13d0 sound/usb/pcm.c:1611 prepare_outbound_urb+0x377/0xc50 sound/usb/endpoint.c:333

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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