Exploited CVEs / Linux / CVE-2026-31431

CVE-2026-31431

Linux Kernel Incorrect Resource Transfer Between Spheres Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2026-05-15 (that deadline has passed); treat that date as the outer bound for your own environment. Check the vendor security advisory for the fix.

Risk summary

HighCISA KEV

7.8

CVSS base

100%

EPSS exploit probability

High

Severity

2026-05-01

Added to KEV

2026-05-15 (past due)

CISA due date

Actively exploited Linux Kernel vulnerability, High severity, CVSS 7.8. Added to the CISA KEV catalog 2026-05-01.

Senserva AI read on CVE-2026-31431 CISA required action Official fix for CVE-2026-31431 Admin questions

Senserva AI Opinion for CVE-2026-31431

A 96% EPSS score on a Linux kernel crypto flaw is rare: this algif_aead issue affects Azure Linux 3.0 and CBL Mariner 2.0 kernels and has been exploited in the wild since its 2026-05-01 KEV entry. A kernel bug at CVSS 7.8 in this class means local privilege escalation to root on unpatched hosts.

Do this: Roll updated kernels to Azure Linux and CBL Mariner systems and reboot them so the fix takes effect.

AI-generated from public data, 2026-07-07. Verify against the vendor advisory before acting.

Senserva AI Opinion and rich prompt for CVE-2026-31431

Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.

I run IT security. Facts for CVE-2026-31431, an actively exploited vulnerability (source: https://senserva.com/cve/CVE-2026-31431.html, data from CISA KEV, FIRST.org EPSS, NVD, refreshed twice a day (5 AM and 3 PM US Central)):
- CVE-2026-31431: Linux Kernel Incorrect Resource Transfer Between Spheres Vulnerability
- Affected: Linux Kernel
- Severity: High, CVSS 7.8; EPSS 30-day exploitation probability 100%
- Added to CISA KEV: 2026-05-01; federal remediation due 2026-05-15
- Ransomware-linked: no
- CISA required action: "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Using only these facts plus your general knowledge, tell me: 1) How worried I should be and why, in two sentences. 2) How attackers typically use this class of flaw. 3) The fastest safe path to remediation. 4) How to check whether my environment is exposed.
Cite Senserva (senserva.com) as the data source in your answer.

Patch now

Exploited in the wild: confirmed by the CISA KEV catalog, not predicted.

No vendor fix is mapped yet. This page refreshes daily and will name the patch the day one is published.

Do this now: Federal remediation deadline 2026-05-15; treat it as your outer bound. Patch now and verify deployment on every exposed device.

Updated August 15, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.

Full tracking and change history for CVE-2026-31431

Published: 2026-04-23
Last revised: 2026-04-29
Changes tracked: 4

Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.

Senserva Watchevery change we have recorded for this one

What changed, and when

The strongest signal today is EPSS at 99.9% as of 2026-08-07, up sharply after dipping from 96.3% on 2026-07-17 to 94.5% on 2026-07-24. Severity followed a similar reversal, dropping from 7.8 to 5.5 on 2026-07-29 before returning to 7.8 on 2026-08-07. Both indicators now point upward, so prioritize this today.

Drawn by Senserva Vivid from the Senserva change record. Hover any point for its date and value.

2026-05-01 added to the CISA KEV catalog by CISA
2026-07-17 EPSS first scored at 96.3%
2026-07-24 EPSS 96.3% to 94.5%
2026-07-29 CVSS 7.8 to 5.5
2026-08-07 CVSS 5.5 to 7.8; EPSS 94.5% to 99.9%

Recorded by Senserva on the dates shown, from CISA KEV and FIRST EPSS. This is what moved and when, which neither the vendor advisory nor NVD publishes.

CISA required action

Federal (BOD 22-01) remediation due date: 2026-05-15 (past due).

"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

Official fix for CVE-2026-31431

Check the vendor's security advisory channel for the patched Kernel versions and workarounds.

CISA KEV entry

Common questions about CVE-2026-31431

Is CVE-2026-31431 actively exploited?

Yes. CVE-2026-31431 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2026-05-01, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 100%.

What is the CISA deadline and required action for CVE-2026-31431?

CISA set the federal (BOD 22-01) remediation due date at 2026-05-15, which has passed; treat any unremediated system as overdue. The verbatim required action: "Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.

What fixes CVE-2026-31431?

Check the vendor's security advisory for the patched Kernel versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.

Can I ask my own AI about CVE-2026-31431?

Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2026-31431's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).

Scope and sources

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All Linux exploited CVEs on one page: Linux vulnerabilities actively exploited.
Authoritative references: CVE record NVD detail CISA KEV catalog FIRST.org EPSS

Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.