Linux: Out-of-bounds Read
CVE-2026-64319 is a critical-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 9.1 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. The record lists versions 04fb6ff8b87a0ffff3860ff52bdb2fd04b31ece5, 80cd28b56ab62d3e7ed0a7bf05282e6d3ee5b2a0, 999f6205ede984a786f35f727b01f971b98e215d as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.56% chance of exploitation within 30 days, which is low compared with other CVEs.
Critical severity: a successful attack would have severe impact.
What to do
- Update Linux to 04fb6ff8b87a0ffff3860ff52bdb2fd04b31ece5 or 80cd28b56ab62d3e7ed0a7bf05282e6d3ee5b2a0 or 999f6205ede984a786f35f727b01f971b98e215d or 6d7649c1231dac14d906985d2936967e23041c26, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.6.145 or 6.12.96 or 6.18.39 or 7.1.4, whichever matches your release line, or a later version.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | db1312dd95488b5e6ff362ff66fcf953a46b1821 up to, but not including, 04fb6ff8b87a0ffff3860ff52bdb2fd04b31ece5; db1312dd95488b5e6ff362ff66fcf953a46b1821 up to, but not including, 80cd28b56ab62d3e7ed0a7bf05282e6d3ee5b2a0; db1312dd95488b5e6ff362ff66fcf953a46b1821 up to, but not including, 999f6205ede984a786f35f727b01f971b98e215d; db1312dd95488b5e6ff362ff66fcf953a46b1821 up to, but not including, 6d7649c1231dac14d906985d2936967e23041c26; db1312dd95488b5e6ff362ff66fcf953a46b1821 up to, but not including, caa71b3a43ea5c13fe7141cb019ebcb03b8ac857; db1312dd95488b5e6ff362ff66fcf953a46b1821 up to, but not including, 3a413ece2504c70aa34a20be4dafec04e8c741f9; 6.0 | 04fb6ff8b87a0ffff3860ff52bdb2fd04b31ece5, 80cd28b56ab62d3e7ed0a7bf05282e6d3ee5b2a0, 999f6205ede984a786f35f727b01f971b98e215d, 6d7649c1231dac14d906985d2936967e23041c26, caa71b3a43ea5c13fe7141cb019ebcb03b8ac857, 3a413ece2504c70aa34a20be4dafec04e8c741f9 |
| Linux | Linux Kernel | 6.0 up to, but not including, 6.6.145; 6.7 up to, but not including, 6.12.96; 6.13 up to, but not including, 6.18.39; 6.19 up to, but not including, 7.1.4 | 6.6.145, 6.12.96, 6.18.39, 7.1.4 |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- NoneNothing can be modified.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:H. Scored by CNA.
Official 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.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
- git.kernel.org/stable/c/3a413ece2504c70aa34a20be4dafec04e8c741f9
- git.kernel.org/stable/c/6d7649c1231dac14d906985d2936967e23041c26
- git.kernel.org/stable/c/80cd28b56ab62d3e7ed0a7bf05282e6d3ee5b2a0
- git.kernel.org/stable/c/999f6205ede984a786f35f727b01f971b98e215d
- git.kernel.org/stable/c/caa71b3a43ea5c13fe7141cb019ebcb03b8ac857
Other references
Recent Out-of-bounds Read vulnerabilities
- 8.4 High severity
- 7.1 High severity
- 7.1 High severity
- 7.7 High severity
- 9.1 Critical severity
- 8.2 High severity
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