CyberSecBulletin
CVE-2026-46027NVD status: Modified

Linux: Reachable Assertion

Published Updated By the CyberSecBulletin desk

CVE-2026-46027 is a high-severity reachable assertion vulnerability in Linux, with a CVSS 3.1 base score of 7.5 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 257cdf0c5ced9c0fba8aba501d94b0a5fcef2086, 22546729b96fc873b23065dc49e3d73c45cfb874, 5eedbfd82c2884e0010fdfb3c9446a6ebcadb691 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 0.5% 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 257cdf0c5ced9c0fba8aba501d94b0a5fcef2086 or 22546729b96fc873b23065dc49e3d73c45cfb874 or 5eedbfd82c2884e0010fdfb3c9446a6ebcadb691 or f0858e1d5624bb120b198f2a8528f97a9b0ae069, 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.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0cfdd8f92cac01afbb12e4500514036a2b78756b up to, but not including, 257cdf0c5ced9c0fba8aba501d94b0a5fcef2086; 0cfdd8f92cac01afbb12e4500514036a2b78756b up to, but not including, 22546729b96fc873b23065dc49e3d73c45cfb874; 0cfdd8f92cac01afbb12e4500514036a2b78756b up to, but not including, 5eedbfd82c2884e0010fdfb3c9446a6ebcadb691; 0cfdd8f92cac01afbb12e4500514036a2b78756b up to, but not including, f0858e1d5624bb120b198f2a8528f97a9b0ae069; 0cfdd8f92cac01afbb12e4500514036a2b78756b up to, but not including, 6180a296ca65b08a81914805cbc0f78da5f10a1f; 0cfdd8f92cac01afbb12e4500514036a2b78756b up to, but not including, ea0b5d0fe96356dce38f98375a57c52a04e13712; 0cfdd8f92cac01afbb12e4500514036a2b78756b up to, but not including, 83bcf9228b0501694fb2589ed1d142855a2887f2; 0cfdd8f92cac01afbb12e4500514036a2b78756b up to, but not including, 5a8db80f721deee8e916c2cfdee78decda02ce4f; and 1 more ranges257cdf0c5ced9c0fba8aba501d94b0a5fcef2086, 22546729b96fc873b23065dc49e3d73c45cfb874, 5eedbfd82c2884e0010fdfb3c9446a6ebcadb691, f0858e1d5624bb120b198f2a8528f97a9b0ae069, 6180a296ca65b08a81914805cbc0f78da5f10a1f, ea0b5d0fe96356dce38f98375a57c52a04e13712
LinuxLinux Kernel4.11 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, 6.12.86; 6.13 up to, but not including, 6.18.27; 6.19 up to, but not including, 7.0.45.10.258, 5.15.209, 6.1.175, 6.6.140, 6.12.86, 6.18.27

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
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
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
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: net/smc: avoid early lgr access in smc_clc_wait_msg A CLC decline can be received while the handshake is still in an early stage, before the connection has been associated with a link group. The decline handling in smc_clc_wait_msg() updates link-group level sync state for first-contact declines, but that state only exists after link group setup has completed. Guard the link-group update accordingly and keep the per-socket peer diagnosis handling unchanged. This preserves the existing sync_err handling for established link-group contexts and avoids touching link-group state before it is available.

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

The underlying weakness: Reachable Assertion

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.

How developers prevent this class of flaw

  • If the assertion statement is required (e.g., for security or reliability), change the invoking code to avoid the conditions that trigger the assertion.
  • Consider changing the assertion to some other less fatal error. This might not be easy to implement, since other code may be needed to handle the error.
  • Make sensitive open/close operations non-reachable from directly user-controlled data (e.g. open/close resources)

More Reachable Assertion vulnerabilities (CWE-617)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Reachable Assertion vulnerabilities

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