CVE-2026-99037
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AI Threat Summary
CVE-2026-99037 is a moderate vulnerability affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
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.
Attack Chain
Attacker identifies vulnerable service instances using Shodan, Censys, or active scanning
Attacker crafts malicious payload exploiting CVE-2026-99037 to achieve remote code execution
Attacker executes arbitrary OS commands or shellcode in the context of the vulnerable process
Attacker installs backdoor, cron job, or web shell for persistent access
Attacker uses compromised host as pivot point to access internal network resources
MITRE ATT&CK Techniques
Attacker exploits the vulnerability in an internet-facing service to gain initial access
Post-exploitation shell commands executed through the vulnerability
Attacker downloads malware or tools after gaining code execution
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params |
Remediation
Quick Facts
| CVE ID | CVE-2026-99037 |
| CVSS Score | N/A |
| Published | 2026-10-23 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |
References
- https://git.kernel.org/stable/c/3195e0daf590683992edb4eed322…
- https://git.kernel.org/stable/c/40ea7dfa8cd5f9aed72a55c9ca30…
- https://git.kernel.org/stable/c/962ce265fbf5d87afeb78cf19c12…
- https://git.kernel.org/stable/c/9a0dab8a9d9975dec14a118b55ca…
- https://git.kernel.org/stable/c/a1a875614dae43b43d311bb9e7a7…