s390/vfio_ccw: Limit the number of channel program segments
In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Limit the number of channel program segments 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.
- Published
- Aug 26, 2026
- Updated
- Aug 27, 2026
- EPSS
- 0.2% · 8th percentile
- CWE
- —
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Report tools
Action score
37
Monitor
Low priority for now.
- CVSS
- 37 / 40 · 9.3 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
CNA vs NVD score
- NVD
- —
- CNA · Linux
- 9.3
- NVD has not scored this yet; the score shown is the CNA’s.
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpAffected systems
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Versions reported by the vendor
Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.
Linux Linux
- 4.12affected
- 0a19e61e6d4c6192077ead760ba0a2d350987d4c and later · before 15fb4559a7fdf0b8725e433a71cfd03a1313a48baffected · git
- 0a19e61e6d4c6192077ead760ba0a2d350987d4c and later · before a1625f66eaa1200068a0e2c05bc90e65182fc4e3affected · git
- 0a19e61e6d4c6192077ead760ba0a2d350987d4c and later · before 06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2affected · git
- 0a19e61e6d4c6192077ead760ba0a2d350987d4c and later · before 4ee94790490ae8dcc97df8597f07836c8a81bbcfaffected · git
- 0a19e61e6d4c6192077ead760ba0a2d350987d4c and later · before 5405c90d6a47b3014e74ee0618a162449abbbc93affected · git
- before 4.12not affected · semver
- 6.6.153 and later · up to and including 6.6.*not affected · semver
- 6.12.105 and later · up to and including 6.12.*not affected · semver
- 6.18.46 and later · up to and including 6.18.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | all versions | — |
| Debian:12 | linux-6.12 | before 6.12.107-1~deb12u1 | 6.12.107-1~deb12u1 |
| Debian:13 | linux | before 6.12.105-1 | 6.12.105-1 |
| Debian:14 | linux | before 7.1.10-1 | 7.1.10-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
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- CVE-2026-74309vdpa/octeon_ep: fix IRQ-to-ring mapping in interrupt handler40Plan
- CVE-2026-74280crypto: marvell/octeontx - fix DMA cleanup using wrong loop index40Plan
- CVE-2026-74279crypto: cavium/cpt - fix DMA cleanup using wrong loop index40Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2 | Vendor (CNA) |
| Linux Linux | 15fb4559a7fdf0b8725e433a71cfd03a1313a48b | Vendor (CNA) |
| Linux Linux | 4ee94790490ae8dcc97df8597f07836c8a81bbcf | Vendor (CNA) |
| Linux Linux | 5405c90d6a47b3014e74ee0618a162449abbbc93 | Vendor (CNA) |
| Linux Linux | a1625f66eaa1200068a0e2c05bc90e65182fc4e3 | Vendor (CNA) |
| azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 | 6.6.157.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.12.105-1 · Debian:13 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.107-1~deb12u1 · Debian:12 | Package registry (OSV) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
No credits in the CNA record.
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
No nightly-computed relations.
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
—
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
National notice (Türkiye Cybersecurity Directorate / USOM)
Official security notices citing this record; remediation advice is on the agency's page.
- TR-26-0919 · Aug 27, 2026(Linux Kernel Güvenlik Bildirimi)
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- No account or password is required.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
Impact can extend beyond the vulnerable component (scope changes).
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- None
- User interaction
- None
- Scope
- Changed
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
—
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
nvd-secondary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
MITRE has no CAPEC/ATT&CK mapping for this CWE.
Change log
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
- git.kernel.org/stable/c/06f4d6e5a8af6c2072e8cd39dbc512c683ca7fb2
- git.kernel.org/stable/c/15fb4559a7fdf0b8725e433a71cfd03a1313a48b
- git.kernel.org/stable/c/4ee94790490ae8dcc97df8597f07836c8a81bbcf
- git.kernel.org/stable/c/5405c90d6a47b3014e74ee0618a162449abbbc93
- git.kernel.org/stable/c/a1625f66eaa1200068a0e2c05bc90e65182fc4e3
Vendor advisories and official records. Exploit/PoC links are deliberately left out.