{"id":"CVE-2026-89607","title":"ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet","summary":"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 …","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cvssSource":"cna","cwe":["CWE-787"],"vendor":"Linux","product":"Linux","affected":["Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < 2cd21340163494d312836c77c9fbfe2530b3d075","Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < e2152d491ae62d96a32ed59778680a242af1fbc6","Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < d2802414081184f79a619ede178aeef3aa989793","Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < 33e050cac841498b5175f0f385eee903fd98863c","Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < ccd13eff0e7356d2aa28b127b577e4e5ad4563f5","Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < 14cb36a500a5a3afbc955dbf69dabc565f1a3b26","Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < a419c9ebfc9a40ee56aaad6dc68bfd67d400817b","Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < 5babe9c177c364521e3e682b949c5a8c47f4a441","Linux 2.6.19"],"published":"2026-09-11","updated":"2026-10-19","sourceUpdated":"2026-10-19T08:49:39.398Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89607","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"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89607.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-89607"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2532523"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89607"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89607"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89607.mbox"}],"tags":["cve.org","csaf","vex","red-hat"],"epss":0.00169,"epssPercentile":0.06191,"scores":{"cna":7.8,"vendor":7},"ingestedAt":"2026-09-14T15:23:07.451Z","slug":"CVE-2026-89607","body":"## Overview\n\nIn 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]\n\n## Affected\n\n- `Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < 2cd21340163494d312836c77c9fbfe2530b3d075`\n- `Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < e2152d491ae62d96a32ed59778680a242af1fbc6`\n- `Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < d2802414081184f79a619ede178aeef3aa989793`\n- `Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < 33e050cac841498b5175f0f385eee903fd98863c`\n- `Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < ccd13eff0e7356d2aa28b127b577e4e5ad4563f5`\n- `Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < 14cb36a500a5a3afbc955dbf69dabc565f1a3b26`\n- `Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < a419c9ebfc9a40ee56aaad6dc68bfd67d400817b`\n- `Linux >= 237fead619984cc48818fe12ee0ceada3f55b012 < 5babe9c177c364521e3e682b949c5a8c47f4a441`\n- `Linux 2.6.19`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Important · affected: Red Hat Enterprise Linux 6 · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89607.json)","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224677,"id":"CVE-2026-89607","ts":1792401469496,"field":"cvss","old":"7","new":"7.8"},{"seq":203923,"id":"CVE-2026-89607","ts":1789490223387,"field":"cvss","old":"7.8","new":"7"},{"seq":197865,"id":"CVE-2026-89607","ts":1789384320727,"field":"cvss","old":"6.3","new":"7.8"},{"seq":197864,"id":"CVE-2026-89607","ts":1789384320727,"field":"severity","old":"medium","new":"high"},{"seq":183429,"id":"CVE-2026-89607","ts":1789356675333,"field":"cvss","old":"7.8","new":"6.3"},{"seq":183428,"id":"CVE-2026-89607","ts":1789356675333,"field":"severity","old":"high","new":"medium"},{"seq":153432,"id":"CVE-2026-89607","ts":1789285350489,"field":"cvss","old":null,"new":"7.8"},{"seq":153431,"id":"CVE-2026-89607","ts":1789285350489,"field":"severity","old":"none","new":"high"},{"seq":147061,"id":"CVE-2026-89607","ts":1789270195002,"field":"cvss","old":null,"new":"6.3"},{"seq":147060,"id":"CVE-2026-89607","ts":1789270195002,"field":"severity","old":"none","new":"medium"}]}