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CVE-2026-63912

Linux kernel vulnerability

9.8 CRITICALEPSS 0.71%
  1. Published19 Jul 2026

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Remediation

No fixed version is recorded in the NVD data. Check the vendor advisory for the latest guidance.

Frequently asked

Is CVE-2026-63912 being actively exploited?

CVE-2026-63912 is not in the CISA KEV catalog. Its EPSS exploit probability is 0.71%.

How severe is CVE-2026-63912?

CVE-2026-63912 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.71% probability of exploitation.

How do I fix CVE-2026-63912?

Apply the vendor's patch or advisory guidance, then verify no affected versions remain across your devices.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-63912 against the real software inventory on every managed device, every day. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.