VulnerabilityPublished 23 Oct 2026

CVE-2026-99037: Linux kernel · dm-crypt: reject the lmk IV mode with AEAD ciphers

Source GCVE Database

Authoritative record:CVE-2026-99037· Low

Not known to be exploited · fixed in a1a875614dae43b43d311bb9e7a7a70eed78efe6 : update Linux kernel when convenient.

Data as of 26 Oct 2026, 17:16 UTC

Severity

Low

Rated by Threat Radar · CVSS not yet scored by NVD

EPSS: 0.1% chance of exploitation in 30 days – higher than 6% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in a1a875614dae43b43d311bb9e7a7a70eed78efe6, 3195e0daf590683992edb4eed32269e569e04924, 962ce265fbf5d87afeb78cf19c12e083ab0ffeb8 +2

Exploitation evidence

Disclosed: evidence found.
CVE published 23 Oct 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponised: Public exploit code exists in Metasploit or Exploit-DB, or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

ghsa-9xmg-p5vw-vprw

What to do

Upgrade to a fixed release listed under Affected software.

Affected software

Product	Affected	Fixed in
LinuxLinux	Affected ≥ 33d2f09fcb357fd1861c4959d1d3505492bf91f8, < a1a875614dae43b43d311bb9e7a7a70eed78efe6	Fixed in a1a875614dae43b43d311bb9e7a7a70eed78efe6
LinuxLinux	Affected ≥ 33d2f09fcb357fd1861c4959d1d3505492bf91f8, < 3195e0daf590683992edb4eed32269e569e04924	Fixed in 3195e0daf590683992edb4eed32269e569e04924
LinuxLinux	Affected ≥ 33d2f09fcb357fd1861c4959d1d3505492bf91f8, < 962ce265fbf5d87afeb78cf19c12e083ab0ffeb8	Fixed in 962ce265fbf5d87afeb78cf19c12e083ab0ffeb8
LinuxLinux	Affected ≥ 33d2f09fcb357fd1861c4959d1d3505492bf91f8, < 40ea7dfa8cd5f9aed72a55c9ca3008aee5880e6f	Fixed in 40ea7dfa8cd5f9aed72a55c9ca3008aee5880e6f
LinuxLinux	Affected ≥ 33d2f09fcb357fd1861c4959d1d3505492bf91f8, < 9a0dab8a9d9975dec14a118b55cae2517aea5ca9	Fixed in 9a0dab8a9d9975dec14a118b55cae2517aea5ca9
LinuxLinux	Affected =4.12	Fixed in–

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.

References

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