CVE-2026-90078Hinoki check available

Packet loss via incorrect ingress header lengths

Published Sep 17, 2026 · Updated Sep 17, 2026

Packet loss in Linux Foundation Linux Kernel 5.15 allows attackers to interrupt traffic through the skbmod ingress action. In net/sched/act_skbmod.c, tcf_skbmod_act() adds a MAC-header length to the IP-header length when packet data already starts at the network header, causing skb_ensure_writable() to reject valid short packets. Exposure requires traffic to reach the configured skbmod ECN action; separate unset-header assumptions trigger kernel warnings, without a documented kernel crash or code execution.

CVSS severity3.3
Low
EPSS probability0.21%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Packet loss in Linux Foundation Linux Kernel 5.15 allows attackers to interrupt traffic through the skbmod ingress action. In net/sched/act_skbmod.c, tcf_skbmod_act() adds a MAC-header length to the IP-header length when packet data already starts at the network header, causing skb_ensure_writable() to reject valid short packets. Exposure requires traffic to reach the configured skbmod ECN action; separate unset-header assumptions trigger kernel warnings, without a documented kernel crash or code execution.

The record

CVE
CVE-2026-90078
Published
Sep 17, 2026
Updated
Sep 17, 2026
Vendor
Linux Foundation
Product
Linux Kernel
Classifications
Unavailable
Attack vector
local
Privileges
authenticated

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=5.15
  2. Affected versionversion=56af5e749f20c3a540310c207dcc373f4f09156e <0675cff3c2924eb9b80d9dd250cf56a1140af157
  3. Affected versionversion=56af5e749f20c3a540310c207dcc373f4f09156e <1719865b20b22c88d2a55e922eff5ca31b0841f6
  4. Affected versionversion=56af5e749f20c3a540310c207dcc373f4f09156e <62126464f3a6159c0a3dd89e196ba65bfeb0afc6
  5. Affected versionversion=56af5e749f20c3a540310c207dcc373f4f09156e <81d0d1e64f30d9989c829c0953cd6e6c68d9c5fb
  6. Affected versionversion=56af5e749f20c3a540310c207dcc373f4f09156e <985a37781ade19061400100c2ba0f43979dd4d63
  7. Affected versionversion=56af5e749f20c3a540310c207dcc373f4f09156e <d896843d8d925f0adbba319020595cfb1a7bcd57
  8. Affected versionversion=56af5e749f20c3a540310c207dcc373f4f09156e <e8a2027b7e686784a69b2dfcee841d779919f313

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Linux Foundation · Linux Kernelversion=5.15; version=56af5e749f20c3a540310c207dcc373f4f09156e <0675cff3c2924eb9b80d9dd250cf56a1140af157; version=56af5e749f20c3a540310c207dcc373f4f09156e <1719865b20b22c88d2a55e922eff5ca31b0841f6; version=56af5e749f20c3a540310c207dcc373f4f09156e <62126464f3a6159c0a3dd89e196ba65bfeb0afc6; version=56af5e749f20c3a540310c207dcc373f4f09156e <81d0d1e64f30d9989c829c0953cd6e6c68d9c5fb; version=56af5e749f20c3a540310c207dcc373f4f09156e <985a37781ade19061400100c2ba0f43979dd4d63; version=56af5e749f20c3a540310c207dcc373f4f09156e <d896843d8d925f0adbba319020595cfb1a7bcd57; version=56af5e749f20c3a540310c207dcc373f4f09156e <e8a2027b7e686784a69b2dfcee841d779919f313

Published CVSS scores

3.3Amazon LinuxCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

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)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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