CVE-2026-100081Linux vulnerability
CVE-2026-100081 is a vulnerability in Linux, rated high (7.8 on CVSS 3.1).
Why this priority: High severity, with no exploitation signal yet.
Published · Updated · NVD status: Received
What it is
The record does not classify the weakness yet; the description below says what the reporter found.
How it is reached
An attacker can exploit it by someone who can already run code or sign in on the machine, with an ordinary user account, and nobody has to click anything. Success also depends on conditions the attacker does not fully control.
What an attacker gains
A successful attack can read the data it protects, change data or behaviour and take it offline. The damage can spread past the vulnerable component into others.
Is it being exploited?
There is no public report of exploitation yet.
What to do
- Upgrade Linux to a fixed version for your release line (5.10.274, 5.15.225, 6.1.192).
- Limit who can run code or sign in on the hosts that run it.
Description from NVD
In the Linux kernel, the following vulnerability has been resolved:
xen-netback: defer xenvif_mcast_addr_list_free()
In order for the function to legitimately avoid locking/RCU, it needs to run after all TX/RX processing has finished/stopped: Lookups happen from xenvif_start_xmit(), while adds/removes happen from xenvif_tx_action() (called out of xenvif_poll()).
Move the call out of xenvif_disconnect_data() (the call to the function from connect()'s error path doesn't require any cleaning up there), and put it past the synchronization point in backend_disconnect().
This is XSA-527 / CVE-2026-100081.
What this means for your architecture.
A CVE names a product. Whether it matters depends on where that product sits in your systems: what reaches it, which trust boundary it guards and what it can reach once compromised. Veriom maps your components, their relationships and your trust boundaries from your code, cloud and delivery evidence, so you can see where a component like this sits. The radar itself does not look at your systems.
Components it touches
- Linux. Start from where it runs and what it is connected to.
Trust boundaries in play
- Host boundary. The attacker needs a foothold on the machine first; the flaw turns a small foothold into a bigger one.
- Isolation between components. The impact crosses out of the vulnerable component into others it should be isolated from.
Questions to answer about your own systems
- Where does Linux run in your systems, and at which version?
- Which of those hosts also run code or users you do not fully trust?
- What can it reach once compromised: which data stores, secrets and services?
Read more
More reading
- git.kernel.org/stable/c/0d515c409033c8e2a645a781be3ca76ab825fc8c
- git.kernel.org/stable/c/0e786123e46d08d2247ce93a5435e45ed9f4c5d1
- git.kernel.org/stable/c/34f0f63dc6dc11895a17bb5672451b6b11622c99
- git.kernel.org/stable/c/96e05a8ce243e2207704e2e7a6e7d1172730f515
- git.kernel.org/stable/c/990d123d9eaa3ac6c979eed245658676d65ce0db
- git.kernel.org/stable/c/a6bb2f1fa62c56279bdcdadce28d1310c5e12b62
- git.kernel.org/stable/c/fb38fc58acb26d74fe8f7b19621fafaae3c040ff
- www.openwall.com/lists/oss-security/2026/11/06/10
- xenbits.xen.org/xsa/advisory-527.html
Sources
- CVE records and CVSS scores from the NVD CVE API. This product uses the NVD API but is not endorsed or certified by the NVD.
- Exploitation status from CISA’s Known Exploited Vulnerabilities catalog.
- Exploit likelihood from FIRST’s Exploit Prediction Scoring System (EPSS), refreshed daily.
- Explanations are written by Veriom from fixed templates over each record’s data, not by a person reviewing each CVE. Descriptions are quoted from the records as published.