CVE Catalog

CVE-2026-80550

HighCVSS 7.9
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.14%

3th percentile - higher than 3% of all known CVEs

Summary

In the Linux kernel, in the s390/vfio_ccw subsystem, there is an out-of-bounds check on the CCW array. The loop may check a 257th element, which is out of bounds.

Risk Assessment

Out-of-bounds read can lead to information disclosure or system crash.

Recommendation

Apply the kernel patch that restructures the loop to stop after examining 256 CCWs (indexes 0-255).

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: s390/vfio_ccw: Fix out of bounds check on CCW array The routine ccwchain_calc_length() counts the number of channel command words (CCWs) that are chained together in a single channel program, and rejects anything larger than CCWCHAIN_LEN_MAX (256) CCWs. The loop itself is "do..while (count < 257)", and while the logic in is_cpa_within_range() correctly adjusts between the 0-index array of CCWs and the count of CCWs starting at 1, this means it would look at a possible 257th CCW before ending the loop and (correctly) returning an error. Fix this by restructuring the loop to break as soon as 256 CCWs (thus indexes 0-255) are examined, without looking at memory outside the range.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS