CVE intelligence

CVE-2026-31589

Vulnerability intelligence

Published Apr 24, 2026Sources checked Oct 28, 2026

9.8CRITICALCVSS out of 10

What this means

Review the available evidence

CVE-2026-31589 and is rated Critical severity with a CVSS score of 9.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Ubuntu Security Notices guidance

Vendor revision: Aug 18, 2026

Vendor remediation details

This update corrects flaws in the following subsystems: - x86 architecture; - InfiniBand drivers; - Media drivers; - Network drivers; - Mellanox network drivers; - Texas Instruments network drivers; - NVME drivers; - File systems infrastructure; - SMB network file system; - IPv4 networking; - Network traffic control; - TCP network protocol; - Locking primitives; - Memory management; - IPv6 networking; - Multipath TCP; - Netfilter; - RxRPC session sockets; - SCTP protocol; - SMC sockets; (CVE-2026-31405, CVE-2026-31414, CVE-2026-31501, CVE-2026-31589, CVE-2026-31633, CVE-2026-31636, CVE-2026-31705, CVE-2026-43198, CVE-2026-43379, CVE-2026-43465, CVE-2026-43499, CVE-2026-46113, CVE-2026-46137, CVE-2026-46242, CVE-2026-46331, CVE-2026-52924, CVE-2026-52989, CVE-2026-53086, CVE-2026-53131, CVE

Microsoft Security Response Center guidance

Vendor revision: Apr 29, 2026

CBL-Mariner Releases

Vendor-listed releases

6.6.134.1-2

CISA KEVNot listedBased on the latest collected catalog

EPSS0.4%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-31589?

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

mm: call ->free_folio() directly in folio_unmap_invalidate()

We can only call filemap_free_folio() if we have a reference to (or hold a lock on) the mapping. Otherwise, we've already removed the folio from the mapping so it no longer pins the mapping and the mapping can be removed, causing a use-after-free when accessing mapping->a_ops.

Follow the same pattern as __remove_mapping() and load the free_folio function pointer before dropping the lock on the mapping. That lets us make filemap_free_folio() static as this was the only caller outside filemap.c.

Source: NVD