CVE-2026-80551
CRITICAL 9.3In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Ensure first IDAW remains constant The first IDAW in a list does not need to be on a 2K/4K boundary like all others, and so is read separately to accurately calculate the size of the buffer needed to read the full IDAL. Verify that the address found in the first IDAW is unchanged between reads, to ensure a consistent set of IDAWs being worked with.
Severe if exploited (CVSS 9.3), but no known exploitation and low modeled probability. Patch on a normal cadence.
Exploitation likelihood
0.1%chance of exploitation in 30 days · 4th percentile
Impact if exploited
9.3CVSS 3.1 · CRITICAL
- ConfidentialityHigh
- IntegrityHigh
- AvailabilityHigh
What an attacker needs
- ⚠Access: Requires local access to the host
- ✓Privileges: No account or privileges required
- ✓User interaction: No user interaction needed
- ✓Complexity: No special conditions — reliably repeatable
✓ lowers the bar for an attacker · ⚠ raises it
Proof of concept & exploit code
- github-search Search GitHub for public PoC repos
Test against your own equipment
curl -s https://vulnpedia.com/cve/CVE-2026-80551/poc.jsonMachine-readable PoC index for this CVE (for automation).Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-80551/poc.json
Weakness (CWE)
Not classified.
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
All CVSS metrics
- CRITICAL 9.3 v3.1 · CNA Primary
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H - CRITICAL 9.3 v3.1 · NVD Secondary
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
References
Technical & other
- https://git.kernel.org/stable/c/460b977a4e71cc319fdadf91c193ec3beaa57263
- https://git.kernel.org/stable/c/0d46c2565f173bcddcdcaf44a4f69789a20535e2
- https://git.kernel.org/stable/c/08ef2a82115690d6e229615872ac1731af732497
- https://git.kernel.org/stable/c/fc59e9482117ebdccd6dc7fa8082f8b980fd021e
- https://git.kernel.org/stable/c/565bef268d75bf7df665bce6923a88cd0eb74592