CVE-2026-89607ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet
- 7.8HighCVSS base score
- 0.17%Exploitation in 30 daysEPSS · top 94% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
Description
In the Linux kernel, the following vulnerability has been resolved: ecryptfs: reject oversized encrypted_key_size in parse_tag_3_packet parse_tag_3_packet() set encrypted_key_size from the Tag 3 packet body without bounding it against ECRYPTFS_MAX_KEY_BYTES (64). When encrypted_key_size > 64, decrypt_passphrase_encrypted_session_key() sets decrypted_key_size = encrypted_key_size and performs two out-of-bounds writes: 1. crypto_skcipher_decrypt() writes encrypted_key_size bytes into decrypted_key[64] via scatterlist, overflowing into the parent ecryptfs_auth_tok struct. 2. memcpy(crypt_stat->key, decrypted_key, decrypted_key_size) writes into crypt_stat->key[64], corrupting root_iv, keysig_list, and mutexes in ecryptfs_crypt_stat. Only AES-192 (cipher code 0x08) enables this because it sets crypt_stat->key_size = 24 independently of encrypted_key_size, allowing crypto_skcipher_setkey() to succeed while encrypted_key_size exceeds ECRYPTFS_MAX_KEY_BYTES. The PKI decryption path (parse_tag_65_packet) already validates decrypted_key_size <= ECRYPTFS_MAX_KEY_BYTES; the passphrase path omits this check. Bound encrypted_key_size against ECRYPTFS_MAX_KEY_BYTES (64) rather than ECRYPTFS_MAX_ENCRYPTED_KEY_BYTES (512). The 64-byte limit also protects the 512-byte encrypted_key[] buffer, so the former 512-byte check is removed as redundant. [tyhicks: Adjust the code comment to refer to macros representing the buffer sizes rather than mentioning the buffer size values since they may change in the future]
Timeline
ID reserved
By Linux
Published
- 38 days later
· 38 days later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| NVDNVD · Received | 3.1 | High7.8 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.17% · top 94% of all CVEs (13 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: High 7.8.
Affected products
- affected 237fead619984cc48818fe12ee0ceada3f55b012 – < 2cd21340163494d312836c77c9fbfe2530b3d075
- affected 237fead619984cc48818fe12ee0ceada3f55b012 – < e2152d491ae62d96a32ed59778680a242af1fbc6
- affected 237fead619984cc48818fe12ee0ceada3f55b012 – < d2802414081184f79a619ede178aeef3aa989793
- affected 237fead619984cc48818fe12ee0ceada3f55b012 – < 33e050cac841498b5175f0f385eee903fd98863c
- affected 237fead619984cc48818fe12ee0ceada3f55b012 – < ccd13eff0e7356d2aa28b127b577e4e5ad4563f5
- affected 237fead619984cc48818fe12ee0ceada3f55b012 – < 14cb36a500a5a3afbc955dbf69dabc565f1a3b26
- affected 237fead619984cc48818fe12ee0ceada3f55b012 – < a419c9ebfc9a40ee56aaad6dc68bfd67d400817b
- affected 237fead619984cc48818fe12ee0ceada3f55b012 – < 5babe9c177c364521e3e682b949c5a8c47f4a441
- affected 2.6.19
- unaffected < 2.6.19
- unaffected 5.10.270 – ≤ 5.10.*
- unaffected 5.15.221 – ≤ 5.15.*
- unaffected 6.1.188 – ≤ 6.1.*
- unaffected 6.6.157 – ≤ 6.6.*
- unaffected 6.12.109 – ≤ 6.12.*
- unaffected 6.18.50 – ≤ 6.18.*
- unaffected 7.2.4 – ≤ 7.2.*
- unaffected 7.3 – ≤ *
References
References8
- https://git.kernel.org/stable/c/2cd21340163494d312836c77c9fbfe2530b3d075 (opens in a new tab)
- https://git.kernel.org/stable/c/e2152d491ae62d96a32ed59778680a242af1fbc6 (opens in a new tab)
- https://git.kernel.org/stable/c/d2802414081184f79a619ede178aeef3aa989793 (opens in a new tab)
- https://git.kernel.org/stable/c/33e050cac841498b5175f0f385eee903fd98863c (opens in a new tab)
- https://git.kernel.org/stable/c/ccd13eff0e7356d2aa28b127b577e4e5ad4563f5 (opens in a new tab)
- https://git.kernel.org/stable/c/14cb36a500a5a3afbc955dbf69dabc565f1a3b26 (opens in a new tab)
- https://git.kernel.org/stable/c/a419c9ebfc9a40ee56aaad6dc68bfd67d400817b (opens in a new tab)
- https://git.kernel.org/stable/c/5babe9c177c364521e3e682b949c5a8c47f4a441 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-76519 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://cveledger.app/cve/CVE-2026-89607)Record last updated .