CyberSecBulletin
CVE-2026-46266NVD status: Modified

In the Linux kernel, the following vulnerability has been resolved: inet: RAW sockets using…

Published Updated By the CyberSecBulletin desk

CVE-2026-46266 is a critical-severity improper input validation 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 47276297140ee6712646f9b19fb04fe26daedd01, db76b75ede3810e7cf9cfea5067d4f3e0993768b, 19e42490c89bac9a388f28179e66bebbef350f99 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 0.46% chance of exploitation within 30 days, which is low compared with other CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Update Linux to 47276297140ee6712646f9b19fb04fe26daedd01 or db76b75ede3810e7cf9cfea5067d4f3e0993768b or 19e42490c89bac9a388f28179e66bebbef350f99 or 531c1aec81bfe19d00af13da5531fbb8209e4bd2, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.6.128 or 6.12.75 or 6.18.14 or 6.19.4, whichever matches your release line, or a later version.
  3. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 47276297140ee6712646f9b19fb04fe26daedd01; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, db76b75ede3810e7cf9cfea5067d4f3e0993768b; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 19e42490c89bac9a388f28179e66bebbef350f99; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 531c1aec81bfe19d00af13da5531fbb8209e4bd2; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, 719d3932b8f6e3348ce2f0ac58e278301fc17575; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 up to, but not including, c89477ad79446867394360b29bb801010fc3ff22; 2.6.1247276297140ee6712646f9b19fb04fe26daedd01, db76b75ede3810e7cf9cfea5067d4f3e0993768b, 19e42490c89bac9a388f28179e66bebbef350f99, 531c1aec81bfe19d00af13da5531fbb8209e4bd2, 719d3932b8f6e3348ce2f0ac58e278301fc17575, c89477ad79446867394360b29bb801010fc3ff22
LinuxLinux Kernel2.6.12.1 up to, but not including, 6.6.128; 6.7 up to, but not including, 6.12.75; 6.13 up to, but not including, 6.18.14; 6.19 up to, but not including, 6.19.4; 2.6.126.6.128, 6.12.75, 6.18.14, 6.19.4

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
NoneNo data is disclosed.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

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

Official description

In the Linux kernel, the following vulnerability has been resolved: inet: RAW sockets using IPPROTO_RAW MUST drop incoming ICMP Yizhou Zhao reported that simply having one RAW socket on protocol IPPROTO_RAW (255) was dangerous. socket(AF_INET, SOCK_RAW, 255); A malicious incoming ICMP packet can set the protocol field to 255 and match this socket, leading to FNHE cache changes. inner = IP(src="192.168.2.1", dst="8.8.8.8", proto=255)/Raw("TEST") pkt = IP(src="192.168.1.1", dst="192.168.2.1")/ICMP(type=3, code=4, nexthopmtu=576)/inner "man 7 raw" states: A protocol of IPPROTO_RAW implies enabled IP_HDRINCL and is able to send any IP protocol that is specified in the passed header. Receiving of all IP protocols via IPPROTO_RAW is not possible using raw sockets. Make sure we drop these malicious packets.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How developers prevent this class of flaw

  • Consider using language-theoretic security (LangSec) techniques that characterize inputs using a formal language and build recognizers for that language. This effectively requires parsing to be a distinct layer that effectively enforces a boundary between raw input and internal data representations, instead of allowing parser code to be scattered throughout the program, where it could be subject to errors or inconsistencies that create weaknesses.
  • Use an input validation framework such as Struts or the OWASP ESAPI Validation API. Note that using a framework does not automatically address all input validation problems; be mindful of weaknesses that could arise from misusing the framework itself (CWE-1173).
  • Understand all the potential areas where untrusted inputs can enter the product, including but not limited to: parameters or arguments, cookies, anything read from the network, environment variables, reverse DNS lookups, query results, request headers, URL components, e-mail, files, filenames, databases, and any external systems that provide data to the application. Remember that such inputs may be obtained indirectly through API calls.

More Improper Input Validation vulnerabilities (CWE-20)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: partial).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Improper Input Validation vulnerabilities

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