{"id":"CVE-2026-53388","state":"PUBLISHED","title":"fuse: re-lock request before replacing page cache folio","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: re-lock request before replacing page cache folio\n\nfuse_try_move_folio() unlocks the request on entry but does not\nre-lock it on the success path. This means fuse_chan_abort() can end the\nrequest and free the fuse_io_args (eg fuse_readpages_end()) while the\nsubsequent copy chain logic after fuse_try_move_folio() accesses the\nfuse_io_args, leading to use-after-free issues.\n\nFix this by calling lock_request() before replace_page_cache_folio().\nThis ensures the request is locked on the success path which will\nprevent the fuse_io_args from being freed while the later copying logic\nruns, and also ensures that the ap->folios[i]->mapping is never null\nsince ap->folios[i] will always point to the newfolio after\nreplace_page_cache_folio().","publishedAt":"2026-07-19T11:59:34.456Z","updatedAt":"2026-10-19T20:07:45.789Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"7c18691e0cfda29672f79bafde8abdb7710674f6","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"5927b43a4f8d89e86930f524bf63e9c7e66f61b4","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"030fe3e9d8abdee303dd7e9e42f45082d382a407","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"46473ddccdc5065033e397d6e62c280dbcd3d9c2","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"af2892249d982a1c036ca456cc135374e68b6677","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"0223f452532d9cd8a5e87c45de828fd93c99bd25","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"e28db6ac4792d065ab32565fd9f0a2361c3d4666","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"a078484921052d0badd827fcc2770b5cfc1d4120","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fuse/dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.35","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.35","versionType":"semver"},{"version":"5.15.211","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.177","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.144","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.95","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.37","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.14","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1.2","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fuse/dev.c"]}],"references":["https://git.kernel.org/stable/c/7c18691e0cfda29672f79bafde8abdb7710674f6","https://git.kernel.org/stable/c/5927b43a4f8d89e86930f524bf63e9c7e66f61b4","https://git.kernel.org/stable/c/030fe3e9d8abdee303dd7e9e42f45082d382a407","https://git.kernel.org/stable/c/46473ddccdc5065033e397d6e62c280dbcd3d9c2","https://git.kernel.org/stable/c/af2892249d982a1c036ca456cc135374e68b6677","https://git.kernel.org/stable/c/0223f452532d9cd8a5e87c45de828fd93c99bd25","https://git.kernel.org/stable/c/e28db6ac4792d065ab32565fd9f0a2361c3d4666","https://git.kernel.org/stable/c/a078484921052d0badd827fcc2770b5cfc1d4120"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53388.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53388","state":"PUBLISHED","datePublished":"2026-07-19T11:59:34.456Z","dateUpdated":"2026-10-19T20:07:45.789Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.402Z"},"containers":{"cna":{"title":"fuse: re-lock request before replacing page cache folio","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: re-lock request before replacing page cache folio\n\nfuse_try_move_folio() unlocks the request on entry but does not\nre-lock it on the success path. This means fuse_chan_abort() can end the\nrequest and free the fuse_io_args (eg fuse_readpages_end()) while the\nsubsequent copy chain logic after fuse_try_move_folio() accesses the\nfuse_io_args, leading to use-after-free issues.\n\nFix this by calling lock_request() before replace_page_cache_folio().\nThis ensures the request is locked on the success path which will\nprevent the fuse_io_args from being freed while the later copying logic\nruns, and also ensures that the ap->folios[i]->mapping is never null\nsince ap->folios[i] will always point to the newfolio after\nreplace_page_cache_folio()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"7c18691e0cfda29672f79bafde8abdb7710674f6","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"5927b43a4f8d89e86930f524bf63e9c7e66f61b4","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"030fe3e9d8abdee303dd7e9e42f45082d382a407","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"46473ddccdc5065033e397d6e62c280dbcd3d9c2","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"af2892249d982a1c036ca456cc135374e68b6677","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"0223f452532d9cd8a5e87c45de828fd93c99bd25","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"e28db6ac4792d065ab32565fd9f0a2361c3d4666","versionType":"git"},{"version":"ce534fb052928ce556639d7ecf01cbf4e01321e1","status":"affected","lessThan":"a078484921052d0badd827fcc2770b5cfc1d4120","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fuse/dev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.35","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.35","versionType":"semver"},{"version":"5.15.211","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.177","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.144","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.95","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.37","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.14","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1.2","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/fuse/dev.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/7c18691e0cfda29672f79bafde8abdb7710674f6"},{"url":"https://git.kernel.org/stable/c/5927b43a4f8d89e86930f524bf63e9c7e66f61b4"},{"url":"https://git.kernel.org/stable/c/030fe3e9d8abdee303dd7e9e42f45082d382a407"},{"url":"https://git.kernel.org/stable/c/46473ddccdc5065033e397d6e62c280dbcd3d9c2"},{"url":"https://git.kernel.org/stable/c/af2892249d982a1c036ca456cc135374e68b6677"},{"url":"https://git.kernel.org/stable/c/0223f452532d9cd8a5e87c45de828fd93c99bd25"},{"url":"https://git.kernel.org/stable/c/e28db6ac4792d065ab32565fd9f0a2361c3d4666"},{"url":"https://git.kernel.org/stable/c/a078484921052d0badd827fcc2770b5cfc1d4120"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached only through local syscalls: mounting a FUSE filesystem, reading files to trigger readpages, and the FUSE daemon writing replies to /dev/fuse via splice_write with SPLICE_F_MOVE.\nAC:L - The race is between the attacker's own splice reply and a concurrent abort they trigger (e.g., via sysfs abort or unmount); the attacker controls both threads and can retry until the window is hit.\nPR:L - Exploitation requires mounting and operating a FUSE filesystem via /dev/fuse, which needs local user privileges; on typical systems this is reachable by unprivileged users via user namespaces (CAP_SYS_ADMIN in a user namespace) without init-namespace root.\nUI:N - No victim interaction is required; the attacker mounts the filesystem, runs the FUSE daemon, and triggers the concurrent abort themselves.\nS:U - Impact is kernel memory corruption and potential local privilege escalation within the same kernel security domain, not a cross-boundary escape such as guest-to-host or sandbox breakout.\nC:H - The vulnerability is a use-after-free of fuse_io_args and associated folio pointers in kernel heap memory, which can be leveraged for arbitrary kernel memory read via heap reuse.\nI:H - Use-after-free of fuse_io_args enables heap spraying and controlled reuse of freed kernel objects, providing a path to arbitrary kernel memory write or code execution.\nA:H - The UAF and the race with folio replacement can cause kernel oops/panic, including NULL pointer dereference when fuse_readpages_end accesses a folio with a NULL mapping."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T04:50:39.284Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"5.15.211"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.1.177"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.6.144"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.12.95"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"6.18.37"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"7.0.14"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"7.1.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.35","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-53388","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:30:00.282945Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:07:45.789Z"}}]}}}