{"api_version":"1","generated_at":"2026-07-26T14:51:31+00:00","cve":"CVE-2026-64514","urls":{"html":"https://cve.report/CVE-2026-64514","api":"https://cve.report/api/cve/CVE-2026-64514.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-64514","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64514"},"summary":{"title":"userfaultfd: gate must_wait writability check on pte_present()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nuserfaultfd: gate must_wait writability check on pte_present()\n\nuserfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE\nwithout taking the page table lock and then apply pte_write() /\nhuge_pte_write() to it.  Those accessors decode bits from the present\nencoding only; on a swap or migration entry they read the offset bits that\nhappen to share the same position and return an undefined result.\n\nThe intent of the check is \"is this fault still WP-blocked?\".  A\nnon-marker swap entry means the page is in transit -- the userfault\ncontext the original fault delivered against is no longer the same, and\nthe swap-in or migration completion path will re-deliver a fresh fault if\nuserspace still needs to handle it.  Worst case under the current code the\ngarbage write bit says \"wait\", and the thread stays asleep until a\nUFFDIO_WAKE that may never arrive.\n\nGate the writability check on pte_present() so the lockless re-check only\ninspects present-PTE bits when the entry is actually present.  The\nnon-present, non-marker case returns \"don't wait\" and lets the fault path\nretry.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-07-25 10:17:37","updated_at":"2026-07-25 10:17:37"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/710183888174639a15fcec16cd1af766b8480bb7","name":"https://git.kernel.org/stable/c/710183888174639a15fcec16cd1af766b8480bb7","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d4026417e8184d13850a0bad4d96ceb6ed9f7152","name":"https://git.kernel.org/stable/c/d4026417e8184d13850a0bad4d96ceb6ed9f7152","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0","name":"https://git.kernel.org/stable/c/29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a6e9a4939e359599701b1da351e84f72e021443a","name":"https://git.kernel.org/stable/c/a6e9a4939e359599701b1da351e84f72e021443a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8e80af52db652fbc41320eee45a4f73bc029faf2","name":"https://git.kernel.org/stable/c/8e80af52db652fbc41320eee45a4f73bc029faf2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f","name":"https://git.kernel.org/stable/c/a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5f4dbdb0a87596214076b20b94f2b71b522170b3","name":"https://git.kernel.org/stable/c/5f4dbdb0a87596214076b20b94f2b71b522170b3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/60d696a037eeeedfb57756dfe7ec08a1587c8631","name":"https://git.kernel.org/stable/c/60d696a037eeeedfb57756dfe7ec08a1587c8631","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-64514","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64514","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 369cd2121be440543280b91056de187f625d0dbb a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 369cd2121be440543280b91056de187f625d0dbb d4026417e8184d13850a0bad4d96ceb6ed9f7152 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 369cd2121be440543280b91056de187f625d0dbb 29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 369cd2121be440543280b91056de187f625d0dbb 5f4dbdb0a87596214076b20b94f2b71b522170b3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 369cd2121be440543280b91056de187f625d0dbb a6e9a4939e359599701b1da351e84f72e021443a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 369cd2121be440543280b91056de187f625d0dbb 60d696a037eeeedfb57756dfe7ec08a1587c8631 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 369cd2121be440543280b91056de187f625d0dbb 710183888174639a15fcec16cd1af766b8480bb7 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 369cd2121be440543280b91056de187f625d0dbb 8e80af52db652fbc41320eee45a4f73bc029faf2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.261 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.212 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.178 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.145 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.96 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.39 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.4 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"64514","cve":"CVE-2026-64514","epss":"0.002200000","percentile":"0.125950000","score_date":"2026-07-25","updated_at":"2026-07-26 00:12:33"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["mm/userfaultfd.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f","status":"affected","version":"369cd2121be440543280b91056de187f625d0dbb","versionType":"git"},{"lessThan":"d4026417e8184d13850a0bad4d96ceb6ed9f7152","status":"affected","version":"369cd2121be440543280b91056de187f625d0dbb","versionType":"git"},{"lessThan":"29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0","status":"affected","version":"369cd2121be440543280b91056de187f625d0dbb","versionType":"git"},{"lessThan":"5f4dbdb0a87596214076b20b94f2b71b522170b3","status":"affected","version":"369cd2121be440543280b91056de187f625d0dbb","versionType":"git"},{"lessThan":"a6e9a4939e359599701b1da351e84f72e021443a","status":"affected","version":"369cd2121be440543280b91056de187f625d0dbb","versionType":"git"},{"lessThan":"60d696a037eeeedfb57756dfe7ec08a1587c8631","status":"affected","version":"369cd2121be440543280b91056de187f625d0dbb","versionType":"git"},{"lessThan":"710183888174639a15fcec16cd1af766b8480bb7","status":"affected","version":"369cd2121be440543280b91056de187f625d0dbb","versionType":"git"},{"lessThan":"8e80af52db652fbc41320eee45a4f73bc029faf2","status":"affected","version":"369cd2121be440543280b91056de187f625d0dbb","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["mm/userfaultfd.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.11"},{"lessThan":"4.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.261","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.212","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.178","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.145","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.96","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.39","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.261","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.212","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.178","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.145","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.96","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.39","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.4","versionStartIncluding":"4.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc1","versionStartIncluding":"4.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nuserfaultfd: gate must_wait writability check on pte_present()\n\nuserfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE\nwithout taking the page table lock and then apply pte_write() /\nhuge_pte_write() to it.  Those accessors decode bits from the present\nencoding only; on a swap or migration entry they read the offset bits that\nhappen to share the same position and return an undefined result.\n\nThe intent of the check is \"is this fault still WP-blocked?\".  A\nnon-marker swap entry means the page is in transit -- the userfault\ncontext the original fault delivered against is no longer the same, and\nthe swap-in or migration completion path will re-deliver a fresh fault if\nuserspace still needs to handle it.  Worst case under the current code the\ngarbage write bit says \"wait\", and the thread stays asleep until a\nUFFDIO_WAKE that may never arrive.\n\nGate the writability check on pte_present() so the lockless re-check only\ninspects present-PTE bits when the entry is actually present.  The\nnon-present, non-marker case returns \"don't wait\" and lets the fault path\nretry."}],"providerMetadata":{"dateUpdated":"2026-07-25T08:52:05.878Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/a5700a4c1c9099ac2ac73fe8a09cf059972e0d2f"},{"url":"https://git.kernel.org/stable/c/d4026417e8184d13850a0bad4d96ceb6ed9f7152"},{"url":"https://git.kernel.org/stable/c/29e6f952c5fb7dc1d6b90fe5b7f36063d44ddae0"},{"url":"https://git.kernel.org/stable/c/5f4dbdb0a87596214076b20b94f2b71b522170b3"},{"url":"https://git.kernel.org/stable/c/a6e9a4939e359599701b1da351e84f72e021443a"},{"url":"https://git.kernel.org/stable/c/60d696a037eeeedfb57756dfe7ec08a1587c8631"},{"url":"https://git.kernel.org/stable/c/710183888174639a15fcec16cd1af766b8480bb7"},{"url":"https://git.kernel.org/stable/c/8e80af52db652fbc41320eee45a4f73bc029faf2"}],"title":"userfaultfd: gate must_wait writability check on pte_present()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-64514","datePublished":"2026-07-25T08:52:05.878Z","dateReserved":"2026-07-19T15:36:31.793Z","dateUpdated":"2026-07-25T08:52:05.878Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-07-25 10:17:37","lastModifiedDate":"2026-07-25 10:17:37","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"64514","Ordinal":"1","Title":"userfaultfd: gate must_wait writability check on pte_present()","CVE":"CVE-2026-64514","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"64514","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nuserfaultfd: gate must_wait writability check on pte_present()\n\nuserfaultfd_must_wait() and userfaultfd_huge_must_wait() read the PTE\nwithout taking the page table lock and then apply pte_write() /\nhuge_pte_write() to it.  Those accessors decode bits from the present\nencoding only; on a swap or migration entry they read the offset bits that\nhappen to share the same position and return an undefined result.\n\nThe intent of the check is \"is this fault still WP-blocked?\".  A\nnon-marker swap entry means the page is in transit -- the userfault\ncontext the original fault delivered against is no longer the same, and\nthe swap-in or migration completion path will re-deliver a fresh fault if\nuserspace still needs to handle it.  Worst case under the current code the\ngarbage write bit says \"wait\", and the thread stays asleep until a\nUFFDIO_WAKE that may never arrive.\n\nGate the writability check on pte_present() so the lockless re-check only\ninspects present-PTE bits when the entry is actually present.  The\nnon-present, non-marker case returns \"don't wait\" and lets the fault path\nretry.","Type":"Description","Title":"userfaultfd: gate must_wait writability check on pte_present()"}]}}}