CVE-2026-99037
Received
Received - Intake
dm-crypt AEAD Cipher Rejection with LMK IV Mode
Vulnerability report for CVE-2026-99037, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-23
Last updated on: 2026-10-23
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
dm-crypt: reject the lmk IV mode with AEAD ciphers
A "capi:" table line that pairs an AEAD cipher with the lmk IV mode,
for example "capi:gcm(aes)-lmk" with the integrity:28:aead option,
causes an oops when it is loaded. lmk sets tfms_count to 64, but
crypt_alloc_tfms_aead only allocates one transform, so crypt_setkey
reads past the end of the tfms_aead array and calls crypto_aead_setkey
on the values it finds there.
lmk exists for compatibility with Loop-AES, which uses CBC, so refuse
it with an AEAD cipher rather than allocate 64 AEAD transforms. The
check cannot go in crypt_iv_lmk_ctr with the other lmk checks, because
the IV constructor runs after crypt_set_key.
Note that this is not a security bug because the memory corruption can
only be triggered by root.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 33d2f09fcb357fd1861c4959d1d3505492bf91f8 |
| Linux | Linux | 33d2f09fcb357fd1861c4959d1d3505492bf91f8 |
| Linux | Linux | 33d2f09fcb357fd1861c4959d1d3505492bf91f8 |
| Linux | Linux | 33d2f09fcb357fd1861c4959d1d3505492bf91f8 |
| Linux | Linux | 33d2f09fcb357fd1861c4959d1d3505492bf91f8 |
| Linux | Linux | 4.12 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
