CyberSecBulletin
CVE-2026-64114NVD status: Modified

Linux: Out-of-bounds Read

Published Updated By the CyberSecBulletin desk

CVE-2026-64114 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 1065b9efa4126df559b03a849c139ecfae92cd25, bc20dbd48c26e743f7e0845020c11ed2ce8b15ee, 5a564f737ec54d63e8ee221d3ff396d07586d464 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 0.14% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 1065b9efa4126df559b03a849c139ecfae92cd25 or bc20dbd48c26e743f7e0845020c11ed2ce8b15ee or 5a564f737ec54d63e8ee221d3ff396d07586d464 or 3c5411fa4944ed99af3d9d1de750ea8169b6dac9, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 5.10.258 or 5.15.209 or 6.1.175 or 6.6.142, whichever matches your release line, or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 1065b9efa4126df559b03a849c139ecfae92cd25; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, bc20dbd48c26e743f7e0845020c11ed2ce8b15ee; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 5a564f737ec54d63e8ee221d3ff396d07586d464; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 3c5411fa4944ed99af3d9d1de750ea8169b6dac9; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 145e9afa5b905229b4788bb72c3255f5a5f77508; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 7725cd3b471740fd23d25ed1da722c671fb2a5d3; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, bbe0be67de296176e7243c76e3d9f02f6ae9ff0b; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 915fab69823a14c170dbaa3b41978768e0fe62fc; and 1 more ranges1065b9efa4126df559b03a849c139ecfae92cd25, bc20dbd48c26e743f7e0845020c11ed2ce8b15ee, 5a564f737ec54d63e8ee221d3ff396d07586d464, 3c5411fa4944ed99af3d9d1de750ea8169b6dac9, 145e9afa5b905229b4788bb72c3255f5a5f77508, 7725cd3b471740fd23d25ed1da722c671fb2a5d3
LinuxLinux Kernel2.6.12.1 up to, but not including, 5.10.258; 5.11 up to, but not including, 5.15.209; 5.16 up to, but not including, 6.1.175; 6.2 up to, but not including, 6.6.142; 6.7 up to, but not including, 6.12.92; 6.13 up to, but not including, 6.18.34; 6.19 up to, but not including, 7.0.11; 2.6.12; and 1 more ranges5.10.258, 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34

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
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
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
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by CNA.

Official description

In the Linux kernel, the following vulnerability has been resolved: ipv4: raw: reject IP_HDRINCL packets with ihl < 5 raw_send_hdrinc() validates that the caller-supplied IPv4 header fits within the message length: iphlen = iph->ihl * 4; err = -EINVAL; if (iphlen > length) goto error_free; if (iphlen >= sizeof(*iph)) { /* fix up saddr, tot_len, id, csum, transport_header */ } It does not, however, reject ihl < 5. For such a packet the "if (iphlen >= sizeof(*iph))" branch is skipped, leaving the crafted iphdr untouched, but the packet is still handed to __ip_local_out() and onward. Downstream consumers that read iph->ihl assume a sane value: net/ipv4/ah4.c:ah_output() in particular subtracts sizeof(struct iphdr) from top_iph->ihl * 4 and passes the (signed-int-negative, then cast to size_t) result to memcpy(), producing an OOB access of length close to SIZE_MAX and a host kernel panic. An IPv4 header with ihl < 5 is malformed by definition (RFC 791: "Internet Header Length is the length of the internet header in 32 bit words ... Note that the minimum value for a correct header is 5."). The kernel should not be willing to inject such a packet into its own output path. Reject "iphlen < sizeof(*iph)" alongside the existing "iphlen > length" check. This matches the principle that locally constructed packets that re-enter the IP stack must pass the same basic sanity tests that a foreign packet would be subjected to. Once this lands, the "if (iphlen >= sizeof(*iph))" wrapper around the fixup branch becomes redundant; left in place to keep the patch minimal and backport-friendly. A follow-up can unwrap it. Note that commit 86f4c90a1c5c ("ipv4, ipv6: ensure raw socket message is big enough to hold an IP header") ensures the message buffer is large enough to hold an iphdr, but does not constrain the self-reported iph->ihl. Reachability: the malformed packet source is any caller with CAP_NET_RAW, including an unprivileged process in a user+net namespace on a kernel with CONFIG_USER_NS=y. The reproduced AH crash also requires a matching xfrm AH policy on the outgoing route; a container granted CAP_NET_ADMIN can install that state and policy in its netns. Loopback bypasses xfrm_output, so the trigger uses a real netdev. Reproduced on UML + KASAN: kernel-mode fault at addr 0x0 with memcpy_orig at the crash site. Same shape reproduces inside a rootless Docker container with --cap-add NET_ADMIN on a stock distro kernel.

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.

More Out-of-bounds Read vulnerabilities (CWE-125)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Out-of-bounds Read vulnerabilities

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