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Vulnerability · Published May 27, 2026 · Assigned by Linux

CVE-2026-45952eth: fbnic: Add validation for MTU changes

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 2% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.1%top 97.7% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: Add validation for MTU changes Increasing the MTU beyond the HDS threshold causes the hardware to fragment packets across multiple buffers. If a single-buffer XDP program is attached, the driver will drop all multi-frag frames. While we can't prevent a remote sender from sending non-TCP packets larger than the MTU, this will prevent users from inadvertently breaking new TCP streams. Traditionally, drivers supported XDP with MTU less than 4Kb (packet per page). Fbnic currently prevents attaching XDP when MTU is too high. But it does not prevent increasing MTU after XDP is attached.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:14linux6.18.14-1DEBIAN-CVE-2026-45952
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-aws-6.14no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-gcp-6.14no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-hwe-6.14no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-nvidia-6.11no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-oem-6.14no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-oracle-6.14no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:24.04:LTSlinux-riscv-6.14no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2026-45952
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2026-45952

Affected products (as reported)

VendorProductVersions
Linux Linux 1b0a3950dbd4fa278dc33401a4faba2a23307a16 – before d7eaa006c0444a5d4671be7efe6dbb33ef8b515e1b0a3950dbd4fa278dc33401a4faba2a23307a16 – before 03399063aa0c67fd8bdfd69467ddb849bb3b97df1b0a3950dbd4fa278dc33401a4faba2a23307a16 – before ccd8e87748ad083047d6c8544c5809b7f96cc8df
Linux Linux 6.18

References