# CVE-2026-23408 — Linux

> As of 2026-08-05, CVE-2026-23408 is a HIGH-severity vulnerability in Linux, CVSS v3.1 7.8, EPSS 0.1% (7.0th percentile). Threadlinqs Intelligence links 1 tracked threat campaign to CVE-2026-23408, most recently “Linux Kernel LPE Surge: Copy Fail (CVE-2026-31431), Dirty Frag/Fragnesia (CVE-2026-43284/CVE-2026-43500/CVE-2026-46300), and CrackArmor AppArmor Flaws vs. Defense-in-Depth Mitigations”.

**Last updated:** 2026-08-05

## What is CVE-2026-23408?

In the Linux kernel, the following vulnerability has been resolved: apparmor: Fix double free of ns_name in aa_replace_profiles() if ns_name is NULL after 1071 error = aa_unpack(udata, &lh, &ns_name); and if ent->ns_name contains an ns_name in 1089 } else if (ent->ns_name) { then ns_name is assigned the ent->ns_name 1095 ns_name = ent->ns_name; however ent->ns_name is freed at 1262 aa_load_ent_free(ent); and then again when freeing ns_name at 1270 kfree(ns_name); Fix this by NULLing out ent->ns_name after it is transferred to ns_name ")

Its CVSS v3 base vector states that the flaw requires local access to the host, needs low-privilege credentials, needs no user interaction, and has high impact on confidentiality, integrity, availability. 1 affected-product entry is recorded, across 1 vendor, listed below. The identifier was first published 207 days ago.

## Severity and exploitation probability

- **CVSS v3.1 base score:** 7.8 — HIGH (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **EPSS (FIRST):** 0.1% probability of exploitation in the next 30 days, higher than 7.0% of all scored CVEs
- **CISA KEV:** Not listed in the CISA Known Exploited Vulnerabilities catalog
- **Threadlinqs priority:** 4.2/10 — a Threadlinqs composite of the CVSS base score, the EPSS percentile and public exploit availability
- **Published:** 2026-04-01, last modified 2026-08-05

## Is CVE-2026-23408 being exploited?

It currently carries a trending score of 7 in the Threadlinqs vulnerability feed.

## Affected products and versions

- [Linux](https://intel.threadlinqs.com/vendors/linux): Linux

## How to fix CVE-2026-23408

No vendor patch reference has been recorded for CVE-2026-23408 in the tracked sources. Follow the references below for a fix, and treat the products listed above as exposed until the vendor states otherwise.

## Threat activity tracking CVE-2026-23408

1 tracked threat in the Threadlinqs corpus references CVE-2026-23408, either in the campaign’s CVE list or as an indicator on the campaign record.

- [Linux Kernel LPE Surge: Copy Fail (CVE-2026-31431), Dirty Frag/Fragnesia (CVE-2026-43284/CVE-2026-43500/CVE-2026-46300), and CrackArmor AppArmor Flaws vs. Defense-in-Depth Mitigations](https://intel.threadlinqs.com/threat/TL-2026-2424) — HIGH · 2026-05-29

## Sources

Enriched from CVE.org, FIRST EPSS, GitHub Security Advisories. Last verified by Threadlinqs on 2026-10-10.

**Other references**

- [git.kernel.org](https://git.kernel.org/stable/c/c6347a2116ecccb8fd9ee4ebc75ae41d1d7ef689)
- [git.kernel.org (c053ae381ce227577567d1ef10090ce7506d7a28)](https://git.kernel.org/stable/c/c053ae381ce227577567d1ef10090ce7506d7a28)
- [git.kernel.org (35f4caec1352054b9a61cfdf2bf1898073637aa0)](https://git.kernel.org/stable/c/35f4caec1352054b9a61cfdf2bf1898073637aa0)
- [git.kernel.org (55ef2af7490aaf72f8ffe11ec44c6bcb7eb2162a)](https://git.kernel.org/stable/c/55ef2af7490aaf72f8ffe11ec44c6bcb7eb2162a)
- [git.kernel.org (86feeccd6b93ed94bd6655f30de80f163f8d5a45)](https://git.kernel.org/stable/c/86feeccd6b93ed94bd6655f30de80f163f8d5a45)

_Showing 5 of 8 recorded references._

Canonical: https://intel.threadlinqs.com/cve/CVE-2026-23408
Full detection coverage and IOCs for threats exploiting CVE-2026-23408 via the Threadlinqs MCP server (Purple tier): https://intel.threadlinqs.com/mcp