TUNderflow

TUNderflow CVE-2026-81000 Writeup !WARNING El PoC se proporciona únicamente para ayudar a defensores, mantenedores y equipos de seguridad autorizados a validar parches, mitigaciones, detecciones y exposición en sistemas que poseen o están explícitamente autorizados a probar. Usted es el único...

Astra Linux – Vulnerability found in Linux 5.10, Linux 6.1, Linux, Linux 5.15

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: Fix Use-After-Free in ovsctexit Since kfreercu, which is called during the hlistforeachentryrcu traversal of ovsctlimitexit, is not part of the RCU read critical section, it is possible that the RCU grace period...

Linux Distros Unpatched Vulnerability : CVE-2026-81000

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available. - net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an...

CVE-2026-81000

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

DEBIAN-CVE-2026-81000

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

AZL-100232 CVE-2026-81000 affecting package kernel for versions less than 6.6.157.1-1

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

DEBIAN-CVE-2026-80977

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: don't touch shared zerocopy state in skbtxerror skbtxerror completes the zerocopy uarg and clears SKBFLALLZEROCOPY, and skbzcopydowngrademanaged clears SKBFLMANAGEDFRAGREFS. Both live in skbshinfo, which every clone...

CVE-2026-81000

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

CVE-2026-81000 net: tun: bound receive headroom

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

CVE-2026-81000

CVE-2026-81000 affects the Linux kernel TUN/TAP driver . The root cause is an integer underflow in tun_get_user(): when Open vSwitch (OVS) propagates an oversized headroom request from another port, SKB_MAX_HEAD(align) underflows, causing tun_alloc_skb() to place skb->data outside the allocate...

CVE-2026-81000 net: tun: bound receive headroom

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

EUVD-2026-76323

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

CVE-2026-81000

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

CVE-2026-80977 net: skbuff: don't touch shared zerocopy state in skb_tx_error()

In the Linux kernel, the following vulnerability has been resolved: net: skbuff: don't touch shared zerocopy state in skbtxerror skbtxerror completes the zerocopy uarg and clears SKBFLALLZEROCOPY, and skbzcopydowngrademanaged clears SKBFLMANAGEDFRAGREFS. Both live in skbshinfo, which every clone...

CVE-2026-81000: Undefined Security Weakness

In the Linux kernel, the following vulnerability has been resolved: net: tun: bound receive headroom tungetuser uses tun-align both as skb headroom and when choosing how much packet data to keep linear. OVS can propagate an oversized headroom request from another port to TUN or TAP. When align is...

EulerOS 2.0 SP12 : lxc (EulerOS-SA-2026-3282)

According to the versions of the lxc packages installed, the EulerOS installation on the remote host is affected by the following vulnerabilities : lxc is a Linux container runtime. In the setuid helper lxc-user-nic, the delete path contains a logic flaw in the findline function that allows an...

CVE-2026-74701

In the Linux kernel, the following vulnerability has been resolved: net/openvswitch: check Ethernet header length in keyextract When a packet arrives on an ARPHRDNONE device e.g. TUN, ovsflowkeyextract trusts the user-provided skb-protocol field: if it is ETHPTEB, the packet is classified as...

CVE-2026-74465

A flaw was found in the Linux kernel's Open vSwitch OVS component. When a new meter is attached, the attachmeter function makes it visible to other central processing units CPUs before all checks are complete. If the attachment fails, the meter is freed without waiting for other CPUs to stop usin...

RLSA-2026:53329 Important: kernel security, bug fix, and enhancement update

The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fixes: kernel: cxl/port: Fix use after free of parentport in cxldetachep CVE-2026-31530 kernel: xen: AMD Zen 2 Processors: Privilege escalation via improper CPU cache isolation CVE-2025-54518 kernel:...

PT-2026-90130

Name of the Vulnerable Software and Affected Versions Linux kernel affected versions not specified Description An issue exists in the tun get user function where the tun-align variable is used for both skb headroom and determining the amount of linear packet data. Open vSwitch OVS can propagate a...