{"affected":[{"defaultStatus":"unaffected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"lessThan":"845bf3c6963a52096d0d3866e4a92db77a0c03d8","status":"affected","version":"741a295130606143edbf9fc740f633dbc1e6225f","versionType":"git"},{"lessThan":"d3ffc8f13034af895531a02c30b1fe3a34b46432","status":"affected","version":"741a295130606143edbf9fc740f633dbc1e6225f","versionType":"git"},{"lessThan":"d0d99f60538ddb4a62ccaac2168d8f448965f083","status":"affected","version":"741a295130606143edbf9fc740f633dbc1e6225f","versionType":"git"},{"lessThan":"d7963d6997fea86a6def242ac36198b86655f912","status":"affected","version":"741a295130606143edbf9fc740f633dbc1e6225f","versionType":"git"},{"lessThan":"aa9ebc084505fb26dd90f4d7a249045aad152043","status":"affected","version":"741a295130606143edbf9fc740f633dbc1e6225f","versionType":"git"},{"lessThan":"af8f4be3b68ac8caa41c8e5ead0eeaf5e85e42d0","status":"affected","version":"741a295130606143edbf9fc740f633dbc1e6225f","versionType":"git"},{"lessThan":"42e21e74061b0ebbd859839f81acf10efad02a27","status":"affected","version":"741a295130606143edbf9fc740f633dbc1e6225f","versionType":"git"},{"lessThan":"6c4b2243cb6c0755159bd567130d5e12e7b10d9f","status":"affected","version":"741a295130606143edbf9fc740f633dbc1e6225f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","source":"CNA: Linux","vendor":"Linux","versions":[{"status":"affected","version":"2.6.16"},{"lessThan":"2.6.16","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.253","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.203","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.167","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.130","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.78","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.19","versionType":"semver"},{"lessThanOrEqual":"6.19.*","status":"unaffected","version":"6.19.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.0","versionType":"original_commit_for_fix"}]}],"cpeConfigurations":[{"negate":false,"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.253","versionStartIncluding":"2.6.16.1","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.203","versionStartIncluding":"5.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.167","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.130","versionStartIncluding":"6.2","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.78","versionStartIncluding":"6.7","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.19","versionStartIncluding":"6.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.19.9","versionStartIncluding":"6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.16:-:*:*:*:*:*:*","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.16:rc3:*:*:*:*:*:*","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.16:rc4:*:*:*:*:*:*","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.16:rc5:*:*:*:*:*:*","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.16:rc6:*:*:*:*:*:*","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:2.6.16:rc7:*:*:*:*:*:*","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:7.0:rc1:*:*:*:*:*:*","vulnerable":true}],"negate":false,"operator":"OR"}],"operator":"OR"}],"cveId":"CVE-2026-43472","cwes":["CWE-908"],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nunshare: fix unshare_fs() handling\n\nThere's an unpleasant corner case in unshare(2), when we have a\nCLONE_NEWNS in flags and current->fs hadn't been shared at all; in that\ncase copy_mnt_ns() gets passed current->fs instead of a private copy,\nwhich causes interesting warts in proof of correctness]\n\n> I guess if private means fs->users == 1, the condition could still be true.\n\nUnfortunately, it's worse than just a convoluted proof of correctness.\nConsider the case when we have CLONE_NEWCGROUP in addition to CLONE_NEWNS\n(and current->fs->users == 1).\n\nWe pass current->fs to copy_mnt_ns(), all right.  Suppose it succeeds and\nflips current->fs->{pwd,root} to corresponding locations in the new namespace.\nNow we proceed to copy_cgroup_ns(), which fails (e.g. with -ENOMEM).\nWe call put_mnt_ns() on the namespace created by copy_mnt_ns(), it's\ndestroyed and its mount tree is dissolved, but...  current->fs->root and\ncurrent->fs->pwd are both left pointing to now detached mounts.\n\nThey are pinning those, so it's not a UAF, but it leaves the calling\nprocess with unshare(2) failing with -ENOMEM _and_ leaving it with\npwd and root on detached isolated mounts.  The last part is clearly a bug.\n\nThere is other fun related to that mess (races with pivot_root(), including\nthe one between pivot_root() and fork(), of all things), but this one\nis easy to isolate and fix - treat CLONE_NEWNS as \"allocate a new\nfs_struct even if it hadn't been shared in the first place\".  Sure, we could\ngo for something like \"if both CLONE_NEWNS *and* one of the things that might\nend up failing after copy_mnt_ns() call in create_new_namespaces() are set,\nforce allocation of new fs_struct\", but let's keep it simple - the cost\nof copy_fs_struct() is trivial.\n\nAnother benefit is that copy_mnt_ns() with CLONE_NEWNS *always* gets\na freshly allocated fs_struct, yet to be attached to anything.  That\nseriously simplifies the analysis...\n\nFWIW, that bug had been there since the introduction of unshare(2) ;-/","epss":{"date":"2026-11-06","percentile":0.01499,"score":0.00114},"exploits":[],"kev":null,"metrics":[{"score":5.5,"severity":"medium","source":"NVD: nvd@nist.gov","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}],"modifiedAt":1793981922937,"publishedAt":1778250151556,"references":[{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/845bf3c6963a52096d0d3866e4a92db77a0c03d8"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/d3ffc8f13034af895531a02c30b1fe3a34b46432"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/d0d99f60538ddb4a62ccaac2168d8f448965f083"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/d7963d6997fea86a6def242ac36198b86655f912"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/aa9ebc084505fb26dd90f4d7a249045aad152043"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/af8f4be3b68ac8caa41c8e5ead0eeaf5e85e42d0"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/42e21e74061b0ebbd859839f81acf10efad02a27"},{"source":"CNA: Linux","tags":[],"url":"https://git.kernel.org/stable/c/6c4b2243cb6c0755159bd567130d5e12e7b10d9f"},{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"url":"https://git.kernel.org/stable/c/42e21e74061b0ebbd859839f81acf10efad02a27"},{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"url":"https://git.kernel.org/stable/c/6c4b2243cb6c0755159bd567130d5e12e7b10d9f"},{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"url":"https://git.kernel.org/stable/c/845bf3c6963a52096d0d3866e4a92db77a0c03d8"},{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"url":"https://git.kernel.org/stable/c/aa9ebc084505fb26dd90f4d7a249045aad152043"},{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"url":"https://git.kernel.org/stable/c/af8f4be3b68ac8caa41c8e5ead0eeaf5e85e42d0"},{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"url":"https://git.kernel.org/stable/c/d0d99f60538ddb4a62ccaac2168d8f448965f083"},{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"url":"https://git.kernel.org/stable/c/d3ffc8f13034af895531a02c30b1fe3a34b46432"},{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":["Patch"],"url":"https://git.kernel.org/stable/c/d7963d6997fea86a6def242ac36198b86655f912"}],"remediation":[{"kind":"fix","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://git.kernel.org/stable/c/42e21e74061b0ebbd859839f81acf10efad02a27"},{"kind":"fix","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://git.kernel.org/stable/c/6c4b2243cb6c0755159bd567130d5e12e7b10d9f"},{"kind":"fix","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://git.kernel.org/stable/c/845bf3c6963a52096d0d3866e4a92db77a0c03d8"},{"kind":"fix","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://git.kernel.org/stable/c/aa9ebc084505fb26dd90f4d7a249045aad152043"},{"kind":"fix","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://git.kernel.org/stable/c/af8f4be3b68ac8caa41c8e5ead0eeaf5e85e42d0"},{"kind":"fix","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://git.kernel.org/stable/c/d0d99f60538ddb4a62ccaac2168d8f448965f083"},{"kind":"fix","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://git.kernel.org/stable/c/d3ffc8f13034af895531a02c30b1fe3a34b46432"},{"kind":"fix","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","text":"The reporting source identifies this reference as a patch. Check the advisory for affected versions and supported release branches.","url":"https://git.kernel.org/stable/c/d7963d6997fea86a6def242ac36198b86655f912"}],"revision":"9c7f198ba8aa3330558dfa28b0dcb5602c5e5a85650559af16750cf43e0b61f6","sources":[{"modifiedAt":1793979776209,"name":"CNA: Linux","retrievedAt":1793981722129,"url":"https://www.cve.org/CVERecord?id=CVE-2026-43472"},{"modifiedAt":1793981922937,"name":"NVD","retrievedAt":1793989193519,"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43472"},{"modifiedAt":null,"name":"FIRST EPSS","retrievedAt":1793981730287,"url":"https://api.first.org/data/v1/epss?cve=CVE-2026-43472"}],"ssvc":{"assessedAt":1793979575857,"automatable":"no","exploitation":"none","source":"ADP: CISA-ADP","technicalImpact":"partial"},"status":"published","title":"unshare: fix unshare_fs() handling","updatedAt":1793989193519}