CVE-2026-64319 (CVSS 9.1)

Description

In the Linux kernel, the following vulnerability has been resolved: nvmet-auth: validate reply message payload bounds against transfer length nvmet_auth_reply() accesses the variable-length rval[] array using attacker-controlled hl (hash length) and dhvlen (DH value length) fields without verifying they fit within the allocated buffer of tl bytes. A malicious NVMe-oF initiator can craft a DHCHAP_REPLY message with a small transfer length but large hl/dhvlen values, causing out-of-bounds heap reads when the target processes the DH public key (rval + 2*hl) or performs the host response memcmp. With DH authentication configured, the OOB pointer is passed directly to sg_init_one() and read by crypto_kpp_compute_shared_secret(), reaching up to 526 bytes past the buffer. This is exploitable pre-authentication. Add bounds validation ensuring sizeof(*data) + 2*hl + dhvlen <= tl before any access to the variable-length fields. Discovered by Atuin - Automated Vulnerability Discovery Engine.

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CVSS v3.1 Score

9.1

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H

EPSS — Exploit Prediction

0.0052

Probability of exploitation

0.42%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/3a413ece2504c70aa34a20be4dafec04e8c741f9 https://git.kernel.org/stable/c/6d7649c1231dac14d906985d2936967e23041c26 https://git.kernel.org/stable/c/80cd28b56ab62d3e7ed0a7bf05282e6d3ee5b2a0 https://git.kernel.org/stable/c/999f6205ede984a786f35f727b01f971b98e215d https://git.kernel.org/stable/c/caa71b3a43ea5c13fe7141cb019ebcb03b8ac857

Frequently Asked Questions

What is CVE-2026-64319? +

In the Linux kernel, the following vulnerability has been resolved: nvmet-auth: validate reply message payload bounds against transfer length nvmet_auth_reply() accesses the variable-length rval[] array using attacker-controlled hl (hash length) and dhvlen (DH value length) fields without verifying they fit within the allocated buffer of tl bytes. A malicious NVMe-oF initiator can craft a DHCHAP_REPLY message with a small transfer length but large hl/dhvlen values, causing out-of-bounds heap reads when the target processes the DH public key (rval + 2*hl) or performs the host response memcmp. With DH authentication configured, the OOB pointer is passed directly to sg_init_one() and read by crypto_kpp_compute_shared_secret(), reaching up to 526 bytes past the buffer. This is exploitable pre-authentication. Add bounds validation ensuring sizeof(*data) + 2*hl + dhvlen <= tl before any access to the variable-length fields. Discovered by Atuin - Automated Vulnerability Discovery Engine. It has a CVSS v3.1 base score of 9.1 (CRITICAL).

How severe is CVE-2026-64319? +

CVE-2026-64319 has a CVSS v3.1 score of 9.1 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0052, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-64319? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-64319