CVE-2026-99037 - Vulnerability Details

- dm-crypt: reject the lmk IV mode with AEAD ciphers

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.

Published: 2026-10-23

Score: 4.4 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Impact

The vulnerability occurs in dm-crypt when an AEAD cipher is paired with the lmk IV mode. The kernel mistakenly allocates only one AEAD transform while the configuration expects 64 transforms, causing a read beyond the array during key setting. The result is a kernel oops, which can be triggered by a root user loading the flawed configuration. This is a local denial of service and does not provide remote code execution.

Affected Systems

The flaw affects the generic Linux kernel wherever dm-crypt is built in and the lmk IV mode is enabled. All kernel releases prior to the patch that include dm-crypt and admit a capi table entry like "capi:gcm(aes)-lmk" are potentially vulnerable. The CNA identifies the impacted vendor as Linux:Linux.

Risk and Exploitability

The CVSS score of 4.4 reflects a moderate local impact. EPSS less than 1% indicates very low probability of exploitation. The vulnerability is not listed in CISA KEV. Attackers need local root to load the offending configuration, so remote exploitation is not possible.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`33d2f09fcb357fd1861c4959d1d3505492bf91f8`	affected	< a04546fa65cbcf4a2774f93f365d747a19abb9b8
`33d2f09fcb357fd1861c4959d1d3505492bf91f8`	affected	< 412d1c1f490ed9ec5bd029883e8a626626613a70
`33d2f09fcb357fd1861c4959d1d3505492bf91f8`	affected	< a50e830ded5a0d0cb9e897d1521716ba654f8c3e
`33d2f09fcb357fd1861c4959d1d3505492bf91f8`	affected	< 9a0dab8a9d9975dec14a118b55cae2517aea5ca9
`33d2f09fcb357fd1861c4959d1d3505492bf91f8`	affected	< 962ce265fbf5d87afeb78cf19c12e083ab0ffeb8
`33d2f09fcb357fd1861c4959d1d3505492bf91f8`	affected	< a1a875614dae43b43d311bb9e7a7a70eed78efe6
`33d2f09fcb357fd1861c4959d1d3505492bf91f8`	affected	< 40ea7dfa8cd5f9aed72a55c9ca3008aee5880e6f
`33d2f09fcb357fd1861c4959d1d3505492bf91f8`	affected	< 3195e0daf590683992edb4eed32269e569e04924

Linux

affected

Version	Status	Constraints
`4.12`	affected	—
`0`	unaffected	< 4.12
`5.10.273`	unaffected	≤ 5.10.*
`5.15.224`	unaffected	≤ 5.15.*
`6.1.191`	unaffected	≤ 6.1.*
`6.6.160`	unaffected	≤ 6.6.*
`6.12.113`	unaffected	≤ 6.12.*
`6.18.57`	unaffected	≤ 6.18.*
`7.2.11`	unaffected	≤ 7.2.*
`7.3`	unaffected	≤ *

No data.

Vendor Product Confidence Versions

Linux

100%

Version	Status	Scheme	Platform
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,9a0dab8a9d9975dec14a118b55cae2517aea5ca9)`	affected	code_commit	—
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,962ce265fbf5d87afeb78cf19c12e083ab0ffeb8)`	affected	code_commit	—
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,a1a875614dae43b43d311bb9e7a7a70eed78efe6)`	affected	code_commit	—
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,40ea7dfa8cd5f9aed72a55c9ca3008aee5880e6f)`	affected	code_commit	—
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,3195e0daf590683992edb4eed32269e569e04924)`	affected	code_commit	—

Linux

100%

Version	Status	Scheme	Platform
`4.12`	affected	semver	—
`[0,4.12)`	unaffected	semver	—
`[6.6.160,6.7.0)`	unaffected	semver	—
`[6.12.113,6.13.0)`	unaffected	semver	—
`[6.18.57,6.19.0)`	unaffected	semver	—
`[7.2.11,7.3.0)`	unaffected	semver	—
`[7.3,*]`	unaffected	generic	—

Linux

Linux Kernel

100%

Version	Status	Scheme	Platform
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,9a0dab8a9d9975dec14a118b55cae2517aea5ca9)`	affected	code_commit	—
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,962ce265fbf5d87afeb78cf19c12e083ab0ffeb8)`	affected	code_commit	—
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,a1a875614dae43b43d311bb9e7a7a70eed78efe6)`	affected	code_commit	—
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,40ea7dfa8cd5f9aed72a55c9ca3008aee5880e6f)`	affected	code_commit	—
`[33d2f09fcb357fd1861c4959d1d3505492bf91f8,3195e0daf590683992edb4eed32269e569e04924)`	affected	code_commit	—

Linux

Linux Kernel

100%

Version	Status	Scheme	Platform
`4.12`	affected	semver	—
`[0,4.12)`	unaffected	semver	—
`[6.6.160,6.7.0)`	unaffected	semver	—
`[6.12.113,6.13.0)`	unaffected	semver	—
`[6.18.57,6.19.0)`	unaffected	semver	—
`[7.2.11,7.3.0)`	unaffected	semver	—
`[7.3,*]`	unaffected	generic	—

Found an issue or want to improve our Enrichment? You can suggest it directly by opening an issue on our dedicated GitHub repository .

Remediation

No solution or workaround provided in the CVE record.

OpenCVE Recommended Actions

Update the kernel to a version that contains the fix for CVE‑2026‑99037.
Remove or correct any 'capi:gcm(aes)-lmk' (or similar AEAD/lmk) entries from the dm‑crypt configuration so the module no longer attempts to use the lmk IV mode with an AEAD cipher.
Monitor system logs for dm‑crypt or kernel oops messages and consider restricting module loads until the fix is applied.

Generated by OpenCVE AI on October 29, 2026 at 19:44 UTC.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required High

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00177.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-99037.mbox
https://git.kernel.org/stable/c/3195e0daf590683992edb4eed32269e569e04924
https://git.kernel.org/stable/c/40ea7dfa8cd5f9aed72a55c9ca3008aee5880e6f
https://git.kernel.org/stable/c/412d1c1f490ed9ec5bd029883e8a626626613a70
https://git.kernel.org/stable/c/962ce265fbf5d87afeb78cf19c12e083ab0ffeb8
https://git.kernel.org/stable/c/9a0dab8a9d9975dec14a118b55cae2517aea5ca9
https://git.kernel.org/stable/c/a04546fa65cbcf4a2774f93f365d747a19abb9b8
https://git.kernel.org/stable/c/a1a875614dae43b43d311bb9e7a7a70eed78efe6
https://git.kernel.org/stable/c/a50e830ded5a0d0cb9e897d1521716ba654f8c3e
https://nvd.nist.gov/vuln/detail/CVE-2026-99037
https://www.cve.org/CVERecord?id=CVE-2026-99037

History

Fri, 30 Oct 2026 13:00:00 +0000

Type	Values Removed	Values Added
References		https://git.kernel.org/stable/c/412d1c1f490ed9ec5bd029883e8a626626613a70 https://git.kernel.org/stable/c/a04546fa65cbcf4a2774f93f365d747a19abb9b8 https://git.kernel.org/stable/c/a50e830ded5a0d0cb9e897d1521716ba654f8c3e

Thu, 29 Oct 2026 12:15:00 +0000

Type	Values Removed	Values Added
References		https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-99037.mbox https://nvd.nist.gov/vuln/detail/CVE-2026-99037 https://www.cve.org/CVERecord?id=CVE-2026-99037
Metrics	threat_severity `None`	cvssV3_1 `{'score': 4.4, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Moderate`

Sat, 24 Oct 2026 00:45:00 +0000

Type	Values Removed	Values Added
First Time appeared		Linux linux
Vendors & Products		Linux linux

Fri, 23 Oct 2026 15:30:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-125

Fri, 23 Oct 2026 12:45:00 +0000

Type	Values Removed	Values Added
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.
Title		dm-crypt: reject the lmk IV mode with AEAD ciphers
First Time appeared		Linux Linux linux Kernel
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel
References		https://git.kernel.org/stable/c/3195e0daf590683992edb4eed32269e569e04924 https://git.kernel.org/stable/c/40ea7dfa8cd5f9aed72a55c9ca3008aee5880e6f https://git.kernel.org/stable/c/962ce265fbf5d87afeb78cf19c12e083ab0ffeb8 https://git.kernel.org/stable/c/9a0dab8a9d9975dec14a118b55cae2517aea5ca9 https://git.kernel.org/stable/c/a1a875614dae43b43d311bb9e7a7a70eed78efe6

Subscriptions

Linux Linux Linux Kernel

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2026-10-23T12:21:54.317Z

Updated: 2026-10-30T12:41:10.478Z

Reserved: 2026-09-25T10:25:14.387Z

Link: CVE-2026-99037

Vulnrichment

No data.

NVD

Status : Received

Published: 2026-10-23T13:17:26.947

Modified: 2026-10-30T13:21:40.797

Link: CVE-2026-99037

Redhat

Severity : Moderate

Publid Date: 2026-10-23T00:00:00Z

Links: CVE-2026-99037 - Bugzilla

OpenCVE Enrichment

Updated: 2026-10-29T19:45:11Z

Weaknesses

CWE-125
Out-of-bounds Read

Impact

Affected Systems

Risk and Exploitability

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required High

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

JSON object

JSON object

JSON object

JSON object

JSON object