{"api_version":"1","generated_at":"2026-10-08T10:16:39+00:00","cve":"CVE-2026-89607","urls":{"html":"https://cve.report/CVE-2026-89607","api":"https://cve.report/api/cve/CVE-2026-89607.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89607","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89607"},"summary":{"title":"ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet","description":"In the Linux kernel, the following vulnerability has been resolved:\n\necryptfs: reject oversized encrypted_key_size in parse_tag_3_packet\n\nparse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body\nwithout bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When\nencrypted_key_size > 64, decrypt_passphrase_encrypted_session_key()\nsets decrypted_key_size = encrypted_key_size and performs two\nout-of-bounds writes:\n\n1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into\n   decrypted_key[64] via scatterlist, overflowing into the parent\n   ecryptfs_auth_tok struct.\n2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes\n   into crypt_stat->key[64], corrupting root_iv, keysig_list, and\n   mutexes in ecryptfs_crypt_stat.\n\nOnly AES-192 (cipher code 0x08) enables this because it sets\ncrypt_stat->key_size = 24 independently of encrypted_key_size,\nallowing crypto_skcipher_setkey() to succeed while encrypted_key_size\nexceeds ECRYPTFS_MAX_KEY_BYTES.\n\nThe PKI decryption path (parse_tag_65_packet) already validates\ndecrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path\nomits this check.\n\nBound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather\nthan ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also\nprotects the 512-byte encrypted_key[] buffer, so the former 512-byte\ncheck is removed as redundant.\n\n[tyhicks: Adjust the code comment to refer to macros representing the\n buffer sizes rather than mentioning the buffer size values since they\n may change in the future]","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:45","updated_at":"2026-09-14 13:19:14"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.8","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","data":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/ccd13eff0e7356d2aa28b127b577e4e5ad4563f5","name":"https://git.kernel.org/stable/c/ccd13eff0e7356d2aa28b127b577e4e5ad4563f5","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/14cb36a500a5a3afbc955dbf69dabc565f1a3b26","name":"https://git.kernel.org/stable/c/14cb36a500a5a3afbc955dbf69dabc565f1a3b26","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/d2802414081184f79a619ede178aeef3aa989793","name":"https://git.kernel.org/stable/c/d2802414081184f79a619ede178aeef3aa989793","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e2152d491ae62d96a32ed59778680a242af1fbc6","name":"https://git.kernel.org/stable/c/e2152d491ae62d96a32ed59778680a242af1fbc6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2cd21340163494d312836c77c9fbfe2530b3d075","name":"https://git.kernel.org/stable/c/2cd21340163494d312836c77c9fbfe2530b3d075","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5babe9c177c364521e3e682b949c5a8c47f4a441","name":"https://git.kernel.org/stable/c/5babe9c177c364521e3e682b949c5a8c47f4a441","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/33e050cac841498b5175f0f385eee903fd98863c","name":"https://git.kernel.org/stable/c/33e050cac841498b5175f0f385eee903fd98863c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/a419c9ebfc9a40ee56aaad6dc68bfd67d400817b","name":"https://git.kernel.org/stable/c/a419c9ebfc9a40ee56aaad6dc68bfd67d400817b","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89607","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89607","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 237fead619984cc48818fe12ee0ceada3f55b012 2cd21340163494d312836c77c9fbfe2530b3d075 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 237fead619984cc48818fe12ee0ceada3f55b012 e2152d491ae62d96a32ed59778680a242af1fbc6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 237fead619984cc48818fe12ee0ceada3f55b012 d2802414081184f79a619ede178aeef3aa989793 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 237fead619984cc48818fe12ee0ceada3f55b012 33e050cac841498b5175f0f385eee903fd98863c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 237fead619984cc48818fe12ee0ceada3f55b012 ccd13eff0e7356d2aa28b127b577e4e5ad4563f5 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 237fead619984cc48818fe12ee0ceada3f55b012 14cb36a500a5a3afbc955dbf69dabc565f1a3b26 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 237fead619984cc48818fe12ee0ceada3f55b012 a419c9ebfc9a40ee56aaad6dc68bfd67d400817b git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 237fead619984cc48818fe12ee0ceada3f55b012 5babe9c177c364521e3e682b949c5a8c47f4a441 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 2.6.19","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 2.6.19 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.10.270 5.10.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.15.221 5.15.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.188 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.157 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.109 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.50 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"89607","cve":"CVE-2026-89607","epss":"0.001630000","percentile":"0.058580000","score_date":"2026-09-14","updated_at":"2026-09-15 00:00:41"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/ecryptfs/keystore.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"2cd21340163494d312836c77c9fbfe2530b3d075","status":"affected","version":"237fead619984cc48818fe12ee0ceada3f55b012","versionType":"git"},{"lessThan":"e2152d491ae62d96a32ed59778680a242af1fbc6","status":"affected","version":"237fead619984cc48818fe12ee0ceada3f55b012","versionType":"git"},{"lessThan":"d2802414081184f79a619ede178aeef3aa989793","status":"affected","version":"237fead619984cc48818fe12ee0ceada3f55b012","versionType":"git"},{"lessThan":"33e050cac841498b5175f0f385eee903fd98863c","status":"affected","version":"237fead619984cc48818fe12ee0ceada3f55b012","versionType":"git"},{"lessThan":"ccd13eff0e7356d2aa28b127b577e4e5ad4563f5","status":"affected","version":"237fead619984cc48818fe12ee0ceada3f55b012","versionType":"git"},{"lessThan":"14cb36a500a5a3afbc955dbf69dabc565f1a3b26","status":"affected","version":"237fead619984cc48818fe12ee0ceada3f55b012","versionType":"git"},{"lessThan":"a419c9ebfc9a40ee56aaad6dc68bfd67d400817b","status":"affected","version":"237fead619984cc48818fe12ee0ceada3f55b012","versionType":"git"},{"lessThan":"5babe9c177c364521e3e682b949c5a8c47f4a441","status":"affected","version":"237fead619984cc48818fe12ee0ceada3f55b012","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/ecryptfs/keystore.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"2.6.19"},{"lessThan":"2.6.19","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"5.10.*","status":"unaffected","version":"5.10.270","versionType":"semver"},{"lessThanOrEqual":"5.15.*","status":"unaffected","version":"5.15.221","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.188","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.157","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.109","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.50","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.10.270","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"5.15.221","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.188","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.157","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.109","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.50","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.4","versionStartIncluding":"2.6.19","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"2.6.19","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\necryptfs: reject oversized encrypted_key_size in parse_tag_3_packet\n\nparse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body\nwithout bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When\nencrypted_key_size > 64, decrypt_passphrase_encrypted_session_key()\nsets decrypted_key_size = encrypted_key_size and performs two\nout-of-bounds writes:\n\n1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into\n   decrypted_key[64] via scatterlist, overflowing into the parent\n   ecryptfs_auth_tok struct.\n2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes\n   into crypt_stat->key[64], corrupting root_iv, keysig_list, and\n   mutexes in ecryptfs_crypt_stat.\n\nOnly AES-192 (cipher code 0x08) enables this because it sets\ncrypt_stat->key_size = 24 independently of encrypted_key_size,\nallowing crypto_skcipher_setkey() to succeed while encrypted_key_size\nexceeds ECRYPTFS_MAX_KEY_BYTES.\n\nThe PKI decryption path (parse_tag_65_packet) already validates\ndecrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path\nomits this check.\n\nBound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather\nthan ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also\nprotects the 512-byte encrypted_key[] buffer, so the former 512-byte\ncheck is removed as redundant.\n\n[tyhicks: Adjust the code comment to refer to macros representing the\n buffer sizes rather than mentioning the buffer size values since they\n may change in the future]"}],"metrics":[{"cvssV3_1":{"baseScore":7.8,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - Triggered by a local open/setattr on an eCryptfs mount: ecryptfs_open -> read_or_initialize_metadata -> ecryptfs_read_metadata parses attacker-supplied Tag 3 packets from the lower file header (or xattr). The kernel does not process this as network protocol data.\nAC:L - The attacker fully controls the Tag 3 body, including AES-192 cipher code 0x08 and an AES-block-aligned encrypted_key_size of 80-512 bytes. decrypt_passphrase_encrypted_session_key() then overflows deterministically; no race or uninfluenced memory layout is required to trigger the writes.\nPR:L - An unprivileged user reaches this on standard eCryptfs deployments (setuid-root mount.ecryptfs_private and per-user encrypted home/Private). They plant a crafted lower file under their own .Private directory and open it through the already-mounted eCryptfs tree; init-namespace root is not required.\nUI:N - The attacker performs the whole sequence themselves: install a matching passphrase auth token, write the malformed Tag 3/Tag 11 header into their lower directory, and open the file. No action by another user is required.\nS:U - The out-of-bounds writes corrupt kernel heap and eCryptfs inode-private objects in the same kernel security authority. This is local privilege escalation, not a VM, IOMMU, or sandbox boundary crossing.\nC:H - crypto_skcipher_decrypt() and memcpy() write tens to hundreds of bytes past decrypted_key[64] and crypt_stat->key[64], overflowing into reserved/token fields, keysig_list, mutexes, and adjacent slab/inode-cache objects. That heap corruption can be groomed into an arbitrary kernel read.\nI:H - Session-key wrap uses AES-ECB with the attacker's known passphrase-derived key, so the overflow payload is chosen plaintext. Up to 448 bytes past the 64-byte buffers corrupt list_head pointers and neighboring slab objects, yielding a write primitive for control-flow hijack.\nA:H - Corrupting keysig_list, embedded mutexes, and adjacent inode-cache/slab objects causes kernel oops or panic. The attacker can open the crafted file repeatedly to crash the system at will."}]}],"providerMetadata":{"dateUpdated":"2026-09-14T12:01:27.820Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/2cd21340163494d312836c77c9fbfe2530b3d075"},{"url":"https://git.kernel.org/stable/c/e2152d491ae62d96a32ed59778680a242af1fbc6"},{"url":"https://git.kernel.org/stable/c/d2802414081184f79a619ede178aeef3aa989793"},{"url":"https://git.kernel.org/stable/c/33e050cac841498b5175f0f385eee903fd98863c"},{"url":"https://git.kernel.org/stable/c/ccd13eff0e7356d2aa28b127b577e4e5ad4563f5"},{"url":"https://git.kernel.org/stable/c/14cb36a500a5a3afbc955dbf69dabc565f1a3b26"},{"url":"https://git.kernel.org/stable/c/a419c9ebfc9a40ee56aaad6dc68bfd67d400817b"},{"url":"https://git.kernel.org/stable/c/5babe9c177c364521e3e682b949c5a8c47f4a441"}],"title":"ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89607","datePublished":"2026-09-11T19:45:09.583Z","dateReserved":"2026-09-11T19:38:34.733Z","dateUpdated":"2026-09-14T12:01:27.820Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:45","lastModifiedDate":"2026-09-14 13:19:14","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"LOW","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"HIGH","integrityImpact":"HIGH","availabilityImpact":"HIGH"},"exploitabilityScore":1.8,"impactScore":5.9}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89607","Ordinal":"1","Title":"ecryptfs: reject oversized encrypted_key_size in parse_tag_3_pac","CVE":"CVE-2026-89607","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89607","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\necryptfs: reject oversized encrypted_key_size in parse_tag_3_packet\n\nparse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body\nwithout bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When\nencrypted_key_size > 64, decrypt_passphrase_encrypted_session_key()\nsets decrypted_key_size = encrypted_key_size and performs two\nout-of-bounds writes:\n\n1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into\n   decrypted_key[64] via scatterlist, overflowing into the parent\n   ecryptfs_auth_tok struct.\n2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes\n   into crypt_stat->key[64], corrupting root_iv, keysig_list, and\n   mutexes in ecryptfs_crypt_stat.\n\nOnly AES-192 (cipher code 0x08) enables this because it sets\ncrypt_stat->key_size = 24 independently of encrypted_key_size,\nallowing crypto_skcipher_setkey() to succeed while encrypted_key_size\nexceeds ECRYPTFS_MAX_KEY_BYTES.\n\nThe PKI decryption path (parse_tag_65_packet) already validates\ndecrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path\nomits this check.\n\nBound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather\nthan ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also\nprotects the 512-byte encrypted_key[] buffer, so the former 512-byte\ncheck is removed as redundant.\n\n[tyhicks: Adjust the code comment to refer to macros representing the\n buffer sizes rather than mentioning the buffer size values since they\n may change in the future]","Type":"Description","Title":"ecryptfs: reject oversized encrypted_key_size in parse_tag_3_pac"}]}}}