Microsoft Security Response Center guidance
Vendor revision: Apr 29, 2026CBL-Mariner Releases
Vendor-listed releases
- 6.6.134.1-2
Vulnerability intelligence
CVE-2026-31458 and is rated Medium severity with a CVSS score of 5.5. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CBL-Mariner Releases
Vendor-listed releases
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]
Multiple sysfs command paths dereference contexts_arr[0] without first verifying that kdamond->contexts->nr == 1. A user can set nr_contexts to 0 via sysfs while DAMON is running, causing NULL pointer dereferences.
In more detail, the issue can be triggered by privileged users like below.
First, start DAMON and make contexts directory empty (kdamond->contexts->nr == 0).
# damo start # cd /sys/kernel/mm/damon/admin/kdamonds/0 # echo 0 > contexts/nr_contexts
Then, each of below commands will cause the NULL pointer dereference.
# echo update_schemes_stats > state # echo update_schemes_tried_regions > state # echo update_schemes_tried_bytes > state # echo update_schemes_effective_quotas > state # echo update_tuned_intervals > state
Guard all commands (except OFF) at the entry point of damon_sysfs_handle_cmd().
Source: NVD