CVE-2026-31735
Published: May 1, 2026· Updated: May 7, 2026
Official Description
In the Linux kernel, the following vulnerability has been resolved:
iommupt: Fix short gather if the unmap goes into a large mapping
unmap has the odd behavior that it can unmap more than requested if the
ending point lands within the middle of a large or contiguous IOPTE.
In this case the gather should flush everything unmapped which can be
larger than what was requested to be unmapped. The gather was only
flushing the range requested to be unmapped, not extending to the extra
range, resulting in a short invalidation if the caller hits this special
condition.
This was found by the new invalidation/gather test I am adding in
preparation for ARMv8. Claude deduced the root cause.
As far as I remember nothing relies on unmapping a large entry, so this is
likely not a triggerable bug.
Technical Analysis
CVE-2026-31735 requires local access, meaning attackers must already have a foothold on the target system.
Exploitation requires low privileges, which limits the exposure to scenarios where an attacker has already gained initial access.
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 8.8.
The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.
CVSS v3.1 Vector Breakdown
Affected Vendors & Products
Exploit & PoC Resources
Official Patches & Advisories
All References (2)
Quick Facts
Recommended Actions
- →Apply vendor patches immediately
- →Monitor CVE-2026-31735 in threat intel feeds
- →Review IDS/IPS signatures for exploitation attempts