{"api_version":"1","generated_at":"2026-06-03T11:05:53+00:00","cve":"CVE-2026-43492","urls":{"html":"https://cve.report/CVE-2026-43492","api":"https://cve.report/api/cve/CVE-2026-43492.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-43492","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-43492"},"summary":{"title":"lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nlib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()\n\nYiming reports an integer underflow in mpi_read_raw_from_sgl() when\nsubtracting \"lzeros\" from the unsigned \"nbytes\".\n\nFor this to happen, the scatterlist \"sgl\" needs to occupy more bytes\nthan the \"nbytes\" parameter and the first \"nbytes + 1\" bytes of the\nscatterlist must be zero.  Under these conditions, the while loop\niterating over the scatterlist will count more zeroes than \"nbytes\",\nsubtract the number of zeroes from \"nbytes\" and cause the underflow.\n\nWhen commit 2d4d1eea540b (\"lib/mpi: Add mpi sgl helpers\") originally\nintroduced the bug, it couldn't be triggered because all callers of\nmpi_read_raw_from_sgl() passed a scatterlist whose length was equal to\n\"nbytes\".\n\nHowever since commit 63ba4d67594a (\"KEYS: asymmetric: Use new crypto\ninterface without scatterlists\"), the underflow can now actually be\ntriggered.  When invoking a KEYCTL_PKEY_ENCRYPT system call with a\nlarger \"out_len\" than \"in_len\" and filling the \"in\" buffer with zeroes,\ncrypto_akcipher_sync_prep() will create an all-zero scatterlist used for\nboth the \"src\" and \"dst\" member of struct akcipher_request and thereby\nfulfil the conditions to trigger the bug:\n\n  sys_keyctl()\n    keyctl_pkey_e_d_s()\n      asymmetric_key_eds_op()\n        software_key_eds_op()\n          crypto_akcipher_sync_encrypt()\n            crypto_akcipher_sync_prep()\n              crypto_akcipher_encrypt()\n                rsa_enc()\n                  mpi_read_raw_from_sgl()\n\nTo the user this will be visible as a DoS as the kernel spins forever,\ncausing soft lockup splats as a side effect.\n\nFix it.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-05-19 12:16:18","updated_at":"2026-05-19 12:16:18"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/30e513e755bb381afce6fb57cdc8694136193f22","name":"https://git.kernel.org/stable/c/30e513e755bb381afce6fb57cdc8694136193f22","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8c2f1288250a90a4b5cabed5d888d7e3aeed4035","name":"https://git.kernel.org/stable/c/8c2f1288250a90a4b5cabed5d888d7e3aeed4035","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2aa77a18dc7f2670497fe3ee5acbeda0b57659e5","name":"https://git.kernel.org/stable/c/2aa77a18dc7f2670497fe3ee5acbeda0b57659e5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/26d3a97ad46c7a9226ec04d4bf35bd4998a97d16","name":"https://git.kernel.org/stable/c/26d3a97ad46c7a9226ec04d4bf35bd4998a97d16","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8637dfb4c1d8a7026ef681f2477c6de8b71c4003","name":"https://git.kernel.org/stable/c/8637dfb4c1d8a7026ef681f2477c6de8b71c4003","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-43492","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43492","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d4d1eea540b27c72488fd1914674c42473d53df 2aa77a18dc7f2670497fe3ee5acbeda0b57659e5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d4d1eea540b27c72488fd1914674c42473d53df 26d3a97ad46c7a9226ec04d4bf35bd4998a97d16 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d4d1eea540b27c72488fd1914674c42473d53df 8637dfb4c1d8a7026ef681f2477c6de8b71c4003 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d4d1eea540b27c72488fd1914674c42473d53df 30e513e755bb381afce6fb57cdc8694136193f22 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2d4d1eea540b27c72488fd1914674c42473d53df 8c2f1288250a90a4b5cabed5d888d7e3aeed4035 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 4.4","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 4.4 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.140 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.88 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.30 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.0.7 7.0.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"43492","cve":"CVE-2026-43492","epss":"0.000240000","percentile":"0.070660000","score_date":"2026-05-28","updated_at":"2026-05-29 00:13:16"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["lib/crypto/mpi/mpicoder.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"2aa77a18dc7f2670497fe3ee5acbeda0b57659e5","status":"affected","version":"2d4d1eea540b27c72488fd1914674c42473d53df","versionType":"git"},{"lessThan":"26d3a97ad46c7a9226ec04d4bf35bd4998a97d16","status":"affected","version":"2d4d1eea540b27c72488fd1914674c42473d53df","versionType":"git"},{"lessThan":"8637dfb4c1d8a7026ef681f2477c6de8b71c4003","status":"affected","version":"2d4d1eea540b27c72488fd1914674c42473d53df","versionType":"git"},{"lessThan":"30e513e755bb381afce6fb57cdc8694136193f22","status":"affected","version":"2d4d1eea540b27c72488fd1914674c42473d53df","versionType":"git"},{"lessThan":"8c2f1288250a90a4b5cabed5d888d7e3aeed4035","status":"affected","version":"2d4d1eea540b27c72488fd1914674c42473d53df","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["lib/crypto/mpi/mpicoder.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"4.4"},{"lessThan":"4.4","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.140","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.88","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.30","versionType":"semver"},{"lessThanOrEqual":"7.0.*","status":"unaffected","version":"7.0.7","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.1-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.140","versionStartIncluding":"4.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.88","versionStartIncluding":"4.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.30","versionStartIncluding":"4.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.0.7","versionStartIncluding":"4.4","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1-rc1","versionStartIncluding":"4.4","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nlib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()\n\nYiming reports an integer underflow in mpi_read_raw_from_sgl() when\nsubtracting \"lzeros\" from the unsigned \"nbytes\".\n\nFor this to happen, the scatterlist \"sgl\" needs to occupy more bytes\nthan the \"nbytes\" parameter and the first \"nbytes + 1\" bytes of the\nscatterlist must be zero.  Under these conditions, the while loop\niterating over the scatterlist will count more zeroes than \"nbytes\",\nsubtract the number of zeroes from \"nbytes\" and cause the underflow.\n\nWhen commit 2d4d1eea540b (\"lib/mpi: Add mpi sgl helpers\") originally\nintroduced the bug, it couldn't be triggered because all callers of\nmpi_read_raw_from_sgl() passed a scatterlist whose length was equal to\n\"nbytes\".\n\nHowever since commit 63ba4d67594a (\"KEYS: asymmetric: Use new crypto\ninterface without scatterlists\"), the underflow can now actually be\ntriggered.  When invoking a KEYCTL_PKEY_ENCRYPT system call with a\nlarger \"out_len\" than \"in_len\" and filling the \"in\" buffer with zeroes,\ncrypto_akcipher_sync_prep() will create an all-zero scatterlist used for\nboth the \"src\" and \"dst\" member of struct akcipher_request and thereby\nfulfil the conditions to trigger the bug:\n\n  sys_keyctl()\n    keyctl_pkey_e_d_s()\n      asymmetric_key_eds_op()\n        software_key_eds_op()\n          crypto_akcipher_sync_encrypt()\n            crypto_akcipher_sync_prep()\n              crypto_akcipher_encrypt()\n                rsa_enc()\n                  mpi_read_raw_from_sgl()\n\nTo the user this will be visible as a DoS as the kernel spins forever,\ncausing soft lockup splats as a side effect.\n\nFix it."}],"providerMetadata":{"dateUpdated":"2026-05-19T10:44:24.719Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/2aa77a18dc7f2670497fe3ee5acbeda0b57659e5"},{"url":"https://git.kernel.org/stable/c/26d3a97ad46c7a9226ec04d4bf35bd4998a97d16"},{"url":"https://git.kernel.org/stable/c/8637dfb4c1d8a7026ef681f2477c6de8b71c4003"},{"url":"https://git.kernel.org/stable/c/30e513e755bb381afce6fb57cdc8694136193f22"},{"url":"https://git.kernel.org/stable/c/8c2f1288250a90a4b5cabed5d888d7e3aeed4035"}],"title":"lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-43492","datePublished":"2026-05-19T10:44:24.719Z","dateReserved":"2026-05-01T14:12:56.013Z","dateUpdated":"2026-05-19T10:44:24.719Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-05-19 12:16:18","lastModifiedDate":"2026-05-19 12:16:18","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"43492","Ordinal":"1","Title":"lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl(","CVE":"CVE-2026-43492","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"43492","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nlib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl()\n\nYiming reports an integer underflow in mpi_read_raw_from_sgl() when\nsubtracting \"lzeros\" from the unsigned \"nbytes\".\n\nFor this to happen, the scatterlist \"sgl\" needs to occupy more bytes\nthan the \"nbytes\" parameter and the first \"nbytes + 1\" bytes of the\nscatterlist must be zero.  Under these conditions, the while loop\niterating over the scatterlist will count more zeroes than \"nbytes\",\nsubtract the number of zeroes from \"nbytes\" and cause the underflow.\n\nWhen commit 2d4d1eea540b (\"lib/mpi: Add mpi sgl helpers\") originally\nintroduced the bug, it couldn't be triggered because all callers of\nmpi_read_raw_from_sgl() passed a scatterlist whose length was equal to\n\"nbytes\".\n\nHowever since commit 63ba4d67594a (\"KEYS: asymmetric: Use new crypto\ninterface without scatterlists\"), the underflow can now actually be\ntriggered.  When invoking a KEYCTL_PKEY_ENCRYPT system call with a\nlarger \"out_len\" than \"in_len\" and filling the \"in\" buffer with zeroes,\ncrypto_akcipher_sync_prep() will create an all-zero scatterlist used for\nboth the \"src\" and \"dst\" member of struct akcipher_request and thereby\nfulfil the conditions to trigger the bug:\n\n  sys_keyctl()\n    keyctl_pkey_e_d_s()\n      asymmetric_key_eds_op()\n        software_key_eds_op()\n          crypto_akcipher_sync_encrypt()\n            crypto_akcipher_sync_prep()\n              crypto_akcipher_encrypt()\n                rsa_enc()\n                  mpi_read_raw_from_sgl()\n\nTo the user this will be visible as a DoS as the kernel spins forever,\ncausing soft lockup splats as a side effect.\n\nFix it.","Type":"Description","Title":"lib/crypto: mpi: Fix integer underflow in mpi_read_raw_from_sgl("}]}}}