s390/vfio_ccw: Limit the number of channel program segments
Published Aug 26, 2026
9.3
CRITICALCVSS 3.1
EPSS 0.20%
Description
The processing of channel programs, and the CCWs within them, is done recursively. As such, there is an arbitrary (but not architectural) limit to the number of CCWs that can exist in a single channel program.
The vfio-ccw logic breaks these channel programs into segments whenever it encounters a Transfer-In-Channel (TIC) CCW, and the combined number of segments count towards the global limit. Impose an equivalent limit to the number of segments until such logic can be made non-recursive.
Affected products
-
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version StatusaffectedConstraints
- Version
-
- Version 4.12StatusaffectedConstraints-
- Version 0StatusunaffectedConstraints<4.12
- Version 6.12.105StatusunaffectedConstraints<=6.12.*
- Version 6.18.46StatusunaffectedConstraints<=6.18.*
- Version 6.6.153StatusunaffectedConstraints<=6.6.*
- Version 7.1.10StatusunaffectedConstraints<=7.1.*
- Version 7.2StatusunaffectedConstraints<=*
- Version
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
| ||||||||||||||||||||||||
| Linux | Linux | affected |
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No data.
No data.
Red Hat Enterprise Linux 10
kernel
Fix deferred
Red Hat Enterprise Linux 6
kernel
Not affected
Red Hat Enterprise Linux 7
kernel
Not affected
Red Hat Enterprise Linux 7
kernel-rt
Not affected
Red Hat Enterprise Linux 8
kernel
Not affected
Red Hat Enterprise Linux 8
kernel-rt
Not affected
Red Hat Enterprise Linux 9
kernel
Fix deferred
Red Hat Enterprise Linux 9
kernel-rt
Fix deferred
| Product | Package | State | Advisory |
|---|---|---|---|
| Red Hat Enterprise Linux 10 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 6 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 7 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel | Not affected | n/a |
| Red Hat Enterprise Linux 8 | kernel-rt | Not affected | n/a |
| Red Hat Enterprise Linux 9 | kernel | Fix deferred | n/a |
| Red Hat Enterprise Linux 9 | kernel-rt | Fix deferred | n/a |
No package ranges for this CVE.
Remediation
No remediation recorded yet.
Metrics
No CVSS v4.0 score for this CVE.
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
1 other source (Red Hat) ▾
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
No CVSS v3.0 score for this CVE.
No CVSS v2.0 score for this CVE.
This CVE is not in the KEV list.
No CISA SSVC assessment for this CVE yet.
Estimated probability of exploitation in the wild in the next 30 days (FIRST EPSS). As of Oct 2, 2026.
Score over time
Aug–Oct 2026- EPSS v5
Percentile over time
- EPSS v5
Table of values (2 key points)
Flat stretches are collapsed; showing up to 120 newest points.
| Date | Score | Percentile | Model |
|---|---|---|---|
| Oct 2, 2026 | 0.20% (0.00196) | 8.36th | v5 (v2026.06.15) |
| Aug 27, 2026 | 0.14% (0.00144) | 3.97th | v5 (v2026.06.15) |
References (10)
- https://access.redhat.com/security/cve/CVE-2026-80554 Vendor Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2524419 Issue Tracking
- https://git.kernel.org/stable/c/06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2
- https://git.kernel.org/stable/c/15fb4559a7fdf0b8725e433a71cfd03a1313a48b
- https://git.kernel.org/stable/c/4ee94790490ae8dcc97df8597f07836c8a81bbcf
- https://git.kernel.org/stable/c/5405c90d6a47b3014e74ee0618a162449abbbc93
- https://git.kernel.org/stable/c/a1625f66eaa1200068a0e2c05bc90e65182fc4e3
- https://lore.kernel.org/linux-cve-announce/2026082608-CVE-2026-80554-aead@gregkh/T
- https://nvd.nist.gov/vuln/detail/CVE-2026-80554
- https://www.cve.org/CVERecord?id=CVE-2026-80554
Change history (0)
No recorded changes yet.