CyberSecBulletin
CVE-2026-98107NVD status: Analyzed

Linux: Out-of-bounds Write

Published Updated By the CyberSecBulletin desk

CVE-2026-98107 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 fabc5e04f123225daf980d03f2c5a05e7f0f0a7f, ce0927eb3ee2939fab5ce3f9334bfd2fafb38481, 6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65 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 0.13% 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 fabc5e04f123225daf980d03f2c5a05e7f0f0a7f or ce0927eb3ee2939fab5ce3f9334bfd2fafb38481 or 6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65 or df8c3af6132640da4788e96a02d653e642059803, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.160 or 6.12.111 or 6.18.53 or 7.2.7, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinuxda49b602f7f75ccc91386e1274b3ef71676cd092 up to, but not including, fabc5e04f123225daf980d03f2c5a05e7f0f0a7f; da49b602f7f75ccc91386e1274b3ef71676cd092 up to, but not including, ce0927eb3ee2939fab5ce3f9334bfd2fafb38481; da49b602f7f75ccc91386e1274b3ef71676cd092 up to, but not including, 6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65; da49b602f7f75ccc91386e1274b3ef71676cd092 up to, but not including, df8c3af6132640da4788e96a02d653e642059803; da49b602f7f75ccc91386e1274b3ef71676cd092 up to, but not including, 56c2b5831d39dc84aad2573dc3e197af1a872a05; 5.7fabc5e04f123225daf980d03f2c5a05e7f0f0a7f, ce0927eb3ee2939fab5ce3f9334bfd2fafb38481, 6da5c0331fc3ef0c7b8df8269523fc3b2cce1e65, df8c3af6132640da4788e96a02d653e642059803, 56c2b5831d39dc84aad2573dc3e197af1a872a05
LinuxLinux Kernel5.7 up to, but not including, 6.6.160; 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; 7.36.6.160, 6.12.111, 6.18.53, 7.2.7

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: Bluetooth: L2CAP: fix out-of-bounds write in l2cap_ecred_connect l2cap_chan_connect() tries to ensure there are no more than L2CAP_ECRED_CONN_SCID_MAX pending ECRED channels, so they fit in the same L2CAP_ECRED_CONN_REQ that l2cap_ecred_connect() constructs. However, the check only counts deferred channels. If 6 L2CAP sockets are connected at the same time in order DDDDND (D=deferred, N=non-deferred), the last can bump the total to max+1. It results to one __le16 written out of bounds of the scid array, and an invalid ECRED_CONN_REQ being sent. Fix by leaving room for the non-deferred pending ECRED channels in the counting in l2cap_chan_connect(), so the limit can't be exceeded. Move counting under same critical section where the channel is added. Although race conditions involving this appear unreachable, it's easier to see. Also add WARN_ON_ONCE check in l2cap_ecred_defer_connect() to make this 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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