CVE-2026-90054Network attack vectorHinoki check available

Stream corruption via copied TCP urgent pointers

Published Sep 17, 2026 · Updated Sep 17, 2026

Urgent-data corruption in Linux 4.7 TCP allows remote attackers to corrupt received streams via multi-segment retransmissions. In __tcp_retransmit_skb(), urgent-mode packets are not restricted to one segment, and tcp_gso_segment() copies urg_ptr without adjusting it for each segment's sequence number. Exposure requires outgoing TCP urgent data and multi-segment retransmission; the receiver then delivers the out-of-band byte as ordinary in-band data.

CVSS severity3.7
Low
EPSS probability0.22%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Urgent-data corruption in Linux 4.7 TCP allows remote attackers to corrupt received streams via multi-segment retransmissions. In __tcp_retransmit_skb(), urgent-mode packets are not restricted to one segment, and tcp_gso_segment() copies urg_ptr without adjusting it for each segment's sequence number. Exposure requires outgoing TCP urgent data and multi-segment retransmission; the receiver then delivers the out-of-band byte as ordinary in-band data.

The record

CVE
CVE-2026-90054
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 17, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

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

  1. Affected versionversion=10d3be569243def8d92ac3722395ef5a59c504e6 <3d4e005c198dc410ad568f832bffa7569c059ff8
  2. Affected versionversion=10d3be569243def8d92ac3722395ef5a59c504e6 <47eb90299e6882d6445672530dd7c51ac33ebdbd
  3. Affected versionversion=10d3be569243def8d92ac3722395ef5a59c504e6 <4fd2ee4ac154c204d95d8db72221446dac5af9b8
  4. Affected versionversion=10d3be569243def8d92ac3722395ef5a59c504e6 <711bfd762bec05fb19bc3b17cbb157c39f4e66da
  5. Affected versionversion=10d3be569243def8d92ac3722395ef5a59c504e6 <8eb51013b6308870479a64b4a2a018697b997849
  6. Affected versionversion=10d3be569243def8d92ac3722395ef5a59c504e6 <b8f08a94b2a4addc39249dcf9c792e786108621b
  7. Affected versionversion=10d3be569243def8d92ac3722395ef5a59c504e6 <ce2b807f42ed5e55567b8864ab72963f90779270
  8. Affected versionversion=10d3be569243def8d92ac3722395ef5a59c504e6 <ebe55406404f3cb28e36d2b668e2c6c05026ec29
  9. Affected versionversion=4.7

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=10d3be569243def8d92ac3722395ef5a59c504e6 <3d4e005c198dc410ad568f832bffa7569c059ff8; version=10d3be569243def8d92ac3722395ef5a59c504e6 <47eb90299e6882d6445672530dd7c51ac33ebdbd; version=10d3be569243def8d92ac3722395ef5a59c504e6 <4fd2ee4ac154c204d95d8db72221446dac5af9b8; version=10d3be569243def8d92ac3722395ef5a59c504e6 <711bfd762bec05fb19bc3b17cbb157c39f4e66da; version=10d3be569243def8d92ac3722395ef5a59c504e6 <8eb51013b6308870479a64b4a2a018697b997849; version=10d3be569243def8d92ac3722395ef5a59c504e6 <b8f08a94b2a4addc39249dcf9c792e786108621b; version=10d3be569243def8d92ac3722395ef5a59c504e6 <ce2b807f42ed5e55567b8864ab72963f90779270; version=10d3be569243def8d92ac3722395ef5a59c504e6 <ebe55406404f3cb28e36d2b668e2c6c05026ec29; version=4.7

Published CVSS scores

3.7Amazon LinuxCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N

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.

Activity data is delayed. The latest report is Sep 28, 2026.

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No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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