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CVE-2025-39703

9.8 · CRITICAL
Published Sep 5, 2025 linux CWE-476 EPSS 0.36% (29th pctl)

Overview

CVE-2025-39703 is a critical-severity vulnerability affecting linux linux_kernel. It was published on September 5, 2025 and has a CVSS 3.1 base score of 9.8 (CRITICAL).

This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

net, hsr: reject HSR frame if skb can't hold tag

Receiving HSR frame with insufficient space to hold HSR tag in the skb

can result in a crash (kernel BUG):

[ 45.390915] skbuff: skb_under_panic: text:ffffffff86f32cac len:26 put:14 head:ffff888042418000 data:ffff888042417ff4 tail:0xe end:0x180 dev:bridge_slave_1

[ 45.392559] ------------[ cut here ]------------

[ 45.392912] kernel BUG at net/core/skbuff.c:211!

[ 45.393276] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI

[ 45.393809] CPU: 1 UID: 0 PID: 2496 Comm: reproducer Not tainted 6.15.0 #12 PREEMPT(undef)

[ 45.394433] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014

[ 45.395273] RIP: 0010:skb_panic+0x15b/0x1d0

<snip registers, remove unreliable trace>

[ 45.402911] Call Trace:

[ 45.403105] <IRQ>

[ 45.404470] skb_push+0xcd/0xf0

[ 45.404726] br_dev_queue_pus

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

Vendor Product Versions Status
linux linux_kernel >= 5.10.42, < 5.10.241 Affected

Frequently Asked Questions

What is CVE-2025-39703?

CVE-2025-39703 is a critical-severity vulnerability affecting linux linux_kernel. It was published on September 5, 2025 and has a CVSS 3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2025-39703?

This vulnerability has a CVSS 3.1 base score of 9.8, rated CRITICAL. It can be exploited remotely over the network. No authentication or special privileges are required for exploitation.

How do I fix or remediate CVE-2025-39703?

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

How can CyberStrike help with CVE-2025-39703?

CyberStrike's AI-powered security agents can automatically detect CVE-2025-39703 across your infrastructure using autonomous pentesting, DAST scanning, and HackBrowser. The platform continuously monitors for known vulnerabilities and provides actionable remediation guidance prioritized by real-world exploitability.