CVE-2026-31589
Published: April 24, 2026· Updated: Apr 28, 2026
Official Description
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.
Technical Analysis
CVE-2026-31589 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.
The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.
A successful exploit results in complete confidentiality breach (data exposure), full integrity compromise (data manipulation), availability disruption (denial of service), with a CVSS base score of 9.8.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (3)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-31589 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts