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CVE-2026-98108NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-98108 is a high-severity out-of-bounds write vulnerability in Linux, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited from the same local network by an unauthenticated attacker, without any action from a user. The record lists versions ad0f44a3f1f688558ed876a0702bc2c82b0df689, 564ae0e05e598aa895b9dbd18cb7d6eb64752869, aab17938998b29e75c3324763411aef3e300fc67 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 0.24% 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 ad0f44a3f1f688558ed876a0702bc2c82b0df689 or 564ae0e05e598aa895b9dbd18cb7d6eb64752869 or aab17938998b29e75c3324763411aef3e300fc67 or 0e1fc7cab95ad958e55d70a5dfaaea687c9c639f, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.271 or 5.15.222 or 6.1.189 or 6.6.158, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux15f02b91056253e8cdc592888f431da0731337b8 up to, but not including, ad0f44a3f1f688558ed876a0702bc2c82b0df689; 15f02b91056253e8cdc592888f431da0731337b8 up to, but not including, 564ae0e05e598aa895b9dbd18cb7d6eb64752869; 15f02b91056253e8cdc592888f431da0731337b8 up to, but not including, aab17938998b29e75c3324763411aef3e300fc67; 15f02b91056253e8cdc592888f431da0731337b8 up to, but not including, 0e1fc7cab95ad958e55d70a5dfaaea687c9c639f; 15f02b91056253e8cdc592888f431da0731337b8 up to, but not including, 1074bcc57f741223f9fa82ce6afe5c3d783e4d10; 15f02b91056253e8cdc592888f431da0731337b8 up to, but not including, 5d5a625cbc854d4c4f68e4b16fcf6e682d9a9ed1; 15f02b91056253e8cdc592888f431da0731337b8 up to, but not including, 6cb79e6499228cfdbd4b3301371ce74d01cd2f80; 15f02b91056253e8cdc592888f431da0731337b8 up to, but not including, 4ef05db5b08b176a551b4a6287372045998806b0; and 1 more rangesad0f44a3f1f688558ed876a0702bc2c82b0df689, 564ae0e05e598aa895b9dbd18cb7d6eb64752869, aab17938998b29e75c3324763411aef3e300fc67, 0e1fc7cab95ad958e55d70a5dfaaea687c9c639f, 1074bcc57f741223f9fa82ce6afe5c3d783e4d10, 5d5a625cbc854d4c4f68e4b16fcf6e682d9a9ed1
LinuxLinux Kernel5.7 up to, but not including, 5.10.271; 5.11 up to, but not including, 5.15.222; 5.16 up to, but not including, 6.1.189; 6.2 up to, but not including, 6.6.158; 6.7 up to, but not including, 6.12.111; 6.13 up to, but not including, 6.18.53; 6.19 up to, but not including, 7.2.7; 7.35.10.271, 5.15.222, 6.1.189, 6.6.158, 6.12.111, 6.18.53

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
AdjacentThe attacker must be on the same local network segment.
Attack complexity
HighSuccess depends on conditions outside the attacker's control.
Privileges required
NoneNo account or login is needed.
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:A/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: fix chan mode for LE_CONN_REQ + EXT_FLOWCTL pchan l2cap_new_connection() sets default value of channel mode to match the parent channel. l2cap_le_connect_req() left this at the default, and created L2CAP_MODE_EXT_FLOWCTL channels if listening pchan has that mode. This causes FLAG_DEFER_SETUP channels to reply to L2CAP_LE_CONN_REQ with L2CAP_ECRED_CONN_RSP, which is incorrect. It can also result to stack OOB write (of l2cap_alloc_cid determined values) in l2cap_ecred_rsp_defer(), as l2cap_le_connect_req() does not limit maximum number of deferred channels or check for duplicate ident. Fix by setting chan->mode correctly in l2cap_le_connect_req(). Also check channel mode in l2cap_ecred_rsp_defer(), and do WARN_ON_ONCE instead of OOB write to make it less brittle.

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. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Write vulnerabilities

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