CyberSecBulletin
CVE-2026-46320NVD status: Modified

Linux: Missing Release of Memory after Effective Lifetime

Published Updated By the CyberSecBulletin desk

CVE-2026-46320 is a high-severity missing release of memory after effective lifetime vulnerability in Linux, with a CVSS 3.1 base score of 7.4 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 8d03e65eb6cfbffec471a6b65416f93679bf3286, f979971835dddbca86cf99e3b2e2b94a408a1ab2, 3f52a86a482a69294c50a5a2a097bd6f4104990a 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 0.25% 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 8d03e65eb6cfbffec471a6b65416f93679bf3286 or f979971835dddbca86cf99e3b2e2b94a408a1ab2 or 3f52a86a482a69294c50a5a2a097bd6f4104990a or d30aac0fa00ca0afc3e08174cf7f974a66bdcf05, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.259 or 5.15.210 or 6.1.176 or 6.6.143, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux0efac27791ee068075d80f07c55a229b1335ce12 up to, but not including, 8d03e65eb6cfbffec471a6b65416f93679bf3286; 0efac27791ee068075d80f07c55a229b1335ce12 up to, but not including, f979971835dddbca86cf99e3b2e2b94a408a1ab2; 0efac27791ee068075d80f07c55a229b1335ce12 up to, but not including, 3f52a86a482a69294c50a5a2a097bd6f4104990a; 0efac27791ee068075d80f07c55a229b1335ce12 up to, but not including, d30aac0fa00ca0afc3e08174cf7f974a66bdcf05; 0efac27791ee068075d80f07c55a229b1335ce12 up to, but not including, d68eab61944a9b0826fa2e954e42db1aa3201b7a; 0efac27791ee068075d80f07c55a229b1335ce12 up to, but not including, e27c17346628cb56843a83f93ac63c314c00f388; 0efac27791ee068075d80f07c55a229b1335ce12 up to, but not including, 18a84c35842e19cd3c5534d8cee73d31863f696d; 0efac27791ee068075d80f07c55a229b1335ce12 up to, but not including, 3bcf7aec6a9d16438f2cec29f5d7c8d5b8edf9b2; and 1 more ranges8d03e65eb6cfbffec471a6b65416f93679bf3286, f979971835dddbca86cf99e3b2e2b94a408a1ab2, 3f52a86a482a69294c50a5a2a097bd6f4104990a, d30aac0fa00ca0afc3e08174cf7f974a66bdcf05, d68eab61944a9b0826fa2e954e42db1aa3201b7a, e27c17346628cb56843a83f93ac63c314c00f388
SiemensSIMATIC S7-1500 TM MFP - GNU/Linux subsystemall versionsNot stated
LinuxLinux Kernel4.20 up to, but not including, 5.10.259; 5.11 up to, but not including, 5.15.210; 5.16 up to, but not including, 6.1.176; 6.2 up to, but not including, 6.6.143; 6.7 up to, but not including, 6.12.94; 6.13 up to, but not including, 6.18.36; 6.19 up to, but not including, 7.0.12; 7.15.10.259, 5.15.210, 6.1.176, 6.6.143, 6.12.94, 6.18.36

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
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
ChangedThe attack can reach beyond the vulnerable component into other systems.
Confidentiality
NoneNo data is disclosed.
Integrity
NoneNothing can be modified.
Availability
HighThe component can be taken down completely.

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

Official description

In the Linux kernel, the following vulnerability has been resolved: tap: free page on error paths in tap_get_user_xdp() tap_get_user_xdp() rejects a frame shorter than ETH_HLEN with -EINVAL, and returns -ENOMEM when build_skb() fails. Both paths jump to the err label without freeing the page that vhost_net_build_xdp() allocated for the frame. tap_sendmsg() discards the per-buffer return value and always returns 0, so vhost_tx_batch() takes the success path and never frees the page; each rejected frame in a batch leaks one page-frag chunk. Free the page on both error paths, before the skb is built. This is the tap counterpart of the same leak in tun_xdp_one().

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

The underlying weakness: Missing Release of Memory after Effective Lifetime

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

How developers prevent this class of flaw

  • Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone. For example, glibc in Linux provides protection against free of invalid pointers. When using Xcode to target OS X or iOS, enable automatic reference counting (ARC). To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Consider using the Boehm-Demers-Weiser garbage collector (bdwgc), which can help avoid leaks.

More Missing Release of Memory after Effective Lifetime vulnerabilities (CWE-401)

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 Missing Release of Memory after Effective Lifetime vulnerabilities

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