Go to homepageCyberStrike

Menu

Star on GitHub · 3.2k
Sign inDownload

CVE-2026-63912

9.8 · CRITICAL

In the Linux kernel, the following vulnerability has been resolved: xfrm: esp: restore combined single-frag length gate The ESP out-of-place fast path appends the trailer in esp_output_head() bef…

Published Jul 19, 2026EPSS 0.71%

Overview

CVE-2026-63912 is a critical-severity vulnerability. It was published on July 19, 2026 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:

xfrm: esp: restore combined single-frag length gate

The ESP out-of-place fast path appends the trailer in esp_output_head()

before esp_output_tail() allocates the destination page frag. The

head-side gate currently checks skb->data_len and tailen separately, but

the tail code allocates a single destination frag from the combined

post-trailer skb->data_len.

Reject the page-frag fast path when the combined aligned length exceeds a

page. Otherwise skb_page_frag_refill() may fall back to a single page while

the destination sg still spans the combined skb->data_len.

Restore this combined-length page gate for both IPv4 and IPv6.

Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. 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.

References

Refgit.kernel.org/stable/c/322e48187e0245ab2fff6fec2220b0cae677dbecRefgit.kernel.org/stable/c/36519e3d941fc99d3b52c134dbaf311f987a4708Refgit.kernel.org/stable/c/566295735530ee513326049b0540f32ec050bf2eRefgit.kernel.org/stable/c/5d7ab86e2b6bc23054616bf6ac562013bf60af8cRefgit.kernel.org/stable/c/65f3b3fc2347b89fe21db1e92c7681368415f095Refgit.kernel.org/stable/c/b84091ceddc9f133229dceab3ccc930bf27f9cbaRefgit.kernel.org/stable/c/c093468aea8277f77272a4f199b2e15e19cabb59Refgit.kernel.org/stable/c/dfa0d7b0ff1eb6b2c416b8fdb9b4f2cefba57a40

How CyberStrike helps

Frequently asked questions

What is CVE-2026-63912?

CVE-2026-63912 is a critical-severity vulnerability. It was published on July 19, 2026 and has a CVSS 3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-63912?

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-2026-63912?

Check the references section for vendor advisories, patches, and mitigation guidance. 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-2026-63912?

CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2026-63912 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.

Related CRITICAL CVEs from 2026

View all
Browse by year2026202520242023202220212020201920182017201620152014201320122011201020092008200720062005200420032002200120001999