CVE-2026-80554

Host crash via unbounded channel-program recursion

Published Aug 26, 2026 · Updated Aug 27, 2026

Denial of service in the Linux s390/vfio_ccw component allows guest OS users to crash hosts via crafted channel programs. The parser recursively follows Transfer-In-Channel targets and creates vfio-ccw segments without enforcing the existing global channel-command limit, exhausting the host kernel stack. Exploitation requires an assigned vfio-ccw mediated subchannel; a malicious guest can trigger a host oops or panic that interrupts the host and its virtual machines.

CVSS severity9.3
Critical
EPSS probability0.14%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in the Linux s390/vfio_ccw component allows guest OS users to crash hosts via crafted channel programs. The parser recursively follows Transfer-In-Channel targets and creates vfio-ccw segments without enforcing the existing global channel-command limit, exhausting the host kernel stack. Exploitation requires an assigned vfio-ccw mediated subchannel; a malicious guest can trigger a host oops or panic that interrupts the host and its virtual machines.

The record

CVE
CVE-2026-80554
Published
Aug 26, 2026
Updated
Aug 27, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
CWE-770, T1499
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Aug 26, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 27, 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=0a19e61e6d4c6192077ead760ba0a2d350987d4c <06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2
  2. Affected versionversion=0a19e61e6d4c6192077ead760ba0a2d350987d4c <15fb4559a7fdf0b8725e433a71cfd03a1313a48b
  3. Affected versionversion=0a19e61e6d4c6192077ead760ba0a2d350987d4c <4ee94790490ae8dcc97df8597f07836c8a81bbcf
  4. Affected versionversion=0a19e61e6d4c6192077ead760ba0a2d350987d4c <5405c90d6a47b3014e74ee0618a162449abbbc93
  5. Affected versionversion=0a19e61e6d4c6192077ead760ba0a2d350987d4c <a1625f66eaa1200068a0e2c05bc90e65182fc4e3
  6. Affected versionversion=4.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=0a19e61e6d4c6192077ead760ba0a2d350987d4c <06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2; version=0a19e61e6d4c6192077ead760ba0a2d350987d4c <15fb4559a7fdf0b8725e433a71cfd03a1313a48b; version=0a19e61e6d4c6192077ead760ba0a2d350987d4c <4ee94790490ae8dcc97df8597f07836c8a81bbcf; version=0a19e61e6d4c6192077ead760ba0a2d350987d4c <5405c90d6a47b3014e74ee0618a162449abbbc93; version=0a19e61e6d4c6192077ead760ba0a2d350987d4c <a1625f66eaa1200068a0e2c05bc90e65182fc4e3; version=4.12

Published CVSS scores

5.5Red HatCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
9.3Linux kernel CVE teamCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/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 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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