CVE-2026-98622Public exploitHinoki check available

Host panic via unnecessary conntrack allocation warning

Published Oct 18, 2026 · Updated Oct 18, 2026

A warning-handling flaw in Linux act_ct allows local users to crash the host through packet processing when panic_on_warn is enabled. In net/sched/act_ct.c, tcf_ct_flow_table_add() issues WARN_ON_ONCE when flow_offload_alloc() returns NULL during conntrack teardown or atomic allocation failure, although both are expected conditions. The reported trigger requires a traffic-control ct commit classifier and a concurrent conntrack flush; without panic_on_warn=1, this path produces a warning rather than the described host panic.

CVSS severityUnavailable
Unscored
EPSS probability0.18%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

A warning-handling flaw in Linux act_ct allows local users to crash the host through packet processing when panic_on_warn is enabled. In net/sched/act_ct.c, tcf_ct_flow_table_add() issues WARN_ON_ONCE when flow_offload_alloc() returns NULL during conntrack teardown or atomic allocation failure, although both are expected conditions. The reported trigger requires a traffic-control ct commit classifier and a concurrent conntrack flush; without panic_on_warn=1, this path produces a warning rather than the described host panic.

The record

CVE
CVE-2026-98622
Published
Oct 18, 2026
Updated
Oct 18, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 18, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 18, 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=5.7
  2. Affected versionversion=64ff70b80fd403110b67dd9f7184a604fdb0da43 <00734f3684fcec42c319bedfe68a5d357c720b53
  3. Affected versionversion=64ff70b80fd403110b67dd9f7184a604fdb0da43 <424ba52c0058deeb940d02cba52eb0aeb288db33
  4. Affected versionversion=64ff70b80fd403110b67dd9f7184a604fdb0da43 <47abe7a5c4eb53269aca3506446f851572a059a3
  5. Affected versionversion=64ff70b80fd403110b67dd9f7184a604fdb0da43 <650787233c2fd6e515a7c5f371019a9fa080ccd2
  6. Affected versionversion=64ff70b80fd403110b67dd9f7184a604fdb0da43 <af475f599270e59313552e6c6f3af8507da672b8
  7. Affected versionversion=64ff70b80fd403110b67dd9f7184a604fdb0da43 <d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a
  8. Affected versionversion=64ff70b80fd403110b67dd9f7184a604fdb0da43 <d805560ad69cb266d669341ca01e26bffb0d2c67
  9. Affected versionversion=64ff70b80fd403110b67dd9f7184a604fdb0da43 <e8fcf3f08834e939b797311742ee72b1e2a08096

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.7; version=64ff70b80fd403110b67dd9f7184a604fdb0da43 <00734f3684fcec42c319bedfe68a5d357c720b53; version=64ff70b80fd403110b67dd9f7184a604fdb0da43 <424ba52c0058deeb940d02cba52eb0aeb288db33; version=64ff70b80fd403110b67dd9f7184a604fdb0da43 <47abe7a5c4eb53269aca3506446f851572a059a3; version=64ff70b80fd403110b67dd9f7184a604fdb0da43 <650787233c2fd6e515a7c5f371019a9fa080ccd2; version=64ff70b80fd403110b67dd9f7184a604fdb0da43 <af475f599270e59313552e6c6f3af8507da672b8; version=64ff70b80fd403110b67dd9f7184a604fdb0da43 <d512c484bd93a5f2794aa03c9faeb7bcb82dbd4a; version=64ff70b80fd403110b67dd9f7184a604fdb0da43 <d805560ad69cb266d669341ca01e26bffb0d2c67; version=64ff70b80fd403110b67dd9f7184a604fdb0da43 <e8fcf3f08834e939b797311742ee72b1e2a08096

Published CVSS scores

No CVSS assessment is available in this record.

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 exploitPublished

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

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Technologies

Your stack

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