CVE-2026-43190Network attack vector

Remote crash via TCP option length overread

Published May 6, 2026 · Updated May 6, 2026

Out-of-bounds read in the Linux Kernel allows remote attackers to crash affected systems via malformed TCP options. The xt_tcpmss parser reads beyond a final option byte that is neither EOL nor NOP without first confirming that an option-length byte remains. Exposure requires a tcpmss iptables- or nftables-compatible rule; the one-byte overread can also expose adjacent stack or packet-buffer data.

CVSS severity8.2
High
EPSS probability0.46%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds read in the Linux Kernel allows remote attackers to crash affected systems via malformed TCP options. The xt_tcpmss parser reads beyond a final option byte that is neither EOL nor NOP without first confirming that an option-length byte remains. Exposure requires a tcpmss iptables- or nftables-compatible rule; the one-byte overread can also expose adjacent stack or packet-buffer data.

The record

CVE
CVE-2026-43190
Published
May 6, 2026
Updated
May 6, 2026
Vendor
The Linux Kernel Organization
Product
Linux Kernel
Classifications
CWE-125
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. May 6, 2026CVE publishedPublication date reported by the CVE source.
  2. May 6, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <07a9b32eaae792ff7d0fcac14d8920c937c0a9c3
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5e13d0a37666955b6cfddc0f73cb40ed645b8a05
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <735ee8582da3d239eb0c7a53adca61b79fb228b3
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b300f726640c48c3edfe9c453334dd801f4b74e
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cd5beda7e0e32865e214f28034bb92c1cecff885
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <eaedc0bc18be46fe7f58170e967959a932c4f824
  7. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f6c412dcfd76b0516d51aa847d8f4c7b70381b09
  8. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f895191dc32c53eaf443b6443fe40945b2f92287

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linux Kernelversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <07a9b32eaae792ff7d0fcac14d8920c937c0a9c3; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <5e13d0a37666955b6cfddc0f73cb40ed645b8a05; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <735ee8582da3d239eb0c7a53adca61b79fb228b3; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <8b300f726640c48c3edfe9c453334dd801f4b74e; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <cd5beda7e0e32865e214f28034bb92c1cecff885; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <eaedc0bc18be46fe7f58170e967959a932c4f824; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f6c412dcfd76b0516d51aa847d8f4c7b70381b09; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f895191dc32c53eaf443b6443fe40945b2f92287

Published CVSS scores

8.2Linux kernel CNACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H
5.3Amazon LinuxCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
6.3CanonicalCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
8.2CanonicalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-125Out-of-bounds Read

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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