CVE-2026-80551: s390/vfio_ccw: Ensure first IDAW remains constant
CSIRTS triage
- What
- The first IDAW (Indirect Data Address Word) in s390/vfio_ccw can be modified when it should remain constant, allowing memory manipulation.
- Who is affected
- Systems running Linux kernel with s390 architecture and vfio_ccw support enabled.
- Urgency
- High priority; CVSS 7.1 indicates significant risk and should be patched promptly.
- Action
- Apply a Linux kernel update that enforces immutability of the first IDAW value.
AI-assisted analysis generated from the source advisory — verify against the original.
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Details
Original advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-80551
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-805510.14% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 4% of all EPSS-scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-80551 | coverage & exploitation status | NVD · CVE.org |
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