{"affected":[{"defaultStatus":"unaffected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"lessThan":"aba546061341b56e9ffb37e1eb661a3628b6ec12","status":"affected","version":"0ac32b8affb5a384253dbb8339bd2d0e91add0b7","versionType":"git"},{"lessThan":"1e8da792672481d603fa7cd0d815577220a3ee27","status":"affected","version":"0ac32b8affb5a384253dbb8339bd2d0e91add0b7","versionType":"git"},{"lessThan":"708033c231bd782858f4ddbb46ee874a5a5fbdab","status":"affected","version":"0ac32b8affb5a384253dbb8339bd2d0e91add0b7","versionType":"git"},{"lessThan":"bbe03ad3fb9e714191757ca7b41582f930be7be2","status":"affected","version":"0ac32b8affb5a384253dbb8339bd2d0e91add0b7","versionType":"git"},{"lessThan":"1bfe9fb5ed2667fb075682408b776b5273162615","status":"affected","version":"0ac32b8affb5a384253dbb8339bd2d0e91add0b7","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"status":"affected","version":"5.18"},{"lessThan":"5.18","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.131","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.80","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.21","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.11","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cveId":"CVE-2026-31458","cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]\n\nMultiple sysfs command paths dereference contexts_arr[0] without first\nverifying that kdamond->contexts->nr == 1.  A user can set nr_contexts to\n0 via sysfs while DAMON is running, causing NULL pointer dereferences.\n\nIn more detail, the issue can be triggered by privileged users like\nbelow.\n\nFirst, start DAMON and make contexts directory empty\n(kdamond->contexts->nr == 0).\n\n    # damo start\n    # cd /sys/kernel/mm/damon/admin/kdamonds/0\n    # echo 0 > contexts/nr_contexts\n\nThen, each of below commands will cause the NULL pointer dereference.\n\n    # echo update_schemes_stats > state\n    # echo update_schemes_tried_regions > state\n    # echo update_schemes_tried_bytes > state\n    # echo update_schemes_effective_quotas > state\n    # echo update_tuned_intervals > state\n\nGuard all commands (except OFF) at the entry point of\ndamon_sysfs_handle_cmd().","epss":{"date":"2026-11-05","percentile":0.01986,"score":0.00122},"exploits":[],"kev":null,"metrics":[],"modifiedAt":1793915099942,"publishedAt":1776866030883,"references":[{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/aba546061341b56e9ffb37e1eb661a3628b6ec12"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/1e8da792672481d603fa7cd0d815577220a3ee27"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/708033c231bd782858f4ddbb46ee874a5a5fbdab"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/bbe03ad3fb9e714191757ca7b41582f930be7be2"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/1bfe9fb5ed2667fb075682408b776b5273162615"}],"remediation":[],"revision":"62cf719072b35c874003003b8ae2acef294f52a0129d39483128c932a4e3198f","sources":[{"modifiedAt":1793915099942,"name":"CNA: Linux","retrievedAt":1793917051398,"url":"https://www.cve.org/CVERecord?id=CVE-2026-31458"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793917074880,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-31458"}],"ssvc":{"assessedAt":1793914451121,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]","updatedAt":1793917074880}