CVE-2026-31484

HIGHCVSS 7.1/10EPSS 0.12%

Last modified

CVE-2026-31484 is a high-severity vulnerability rated 7.1/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: io_uring/fdinfo: fix OOB read in SQE_MIXED wrap check __io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte SQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second half of the SQE would be past the end of the sq_sqes array. The current check tests (++sq_head & sq_mask) == 0, but sq_head is only incremented when a 128-byte SQE is encountered, not on every iteration. EPSS estimates a 0.12% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: io_uring/fdinfo: fix OOB read in SQE_MIXED wrap check __io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte SQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second half of the SQE would be past the end of the sq_sqes array. The current check tests (++sq_head & sq_mask) == 0, but sq_head is only incremented when a 128-byte SQE is encountered, not on every iteration. The actual array index is sq_idx = (i + sq_head) & sq_mask, which can be sq_mask (the last slot) while the wrap check passes. Fix by checking sq_idx directly. Keep the sq_head increment so the loop still skips the second half of the 128-byte SQE on the next iteration.

Metrics

CVSS 3.1
7.1/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

EPSS Probability
0.12%

2.0th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 6.19.1, < 6.19.11
LinuxLinux Kernel6.19
LinuxLinux Kernel7.0Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-31484?
In the Linux kernel, the following vulnerability has been resolved: io_uring/fdinfo: fix OOB read in SQE_MIXED wrap check __io_uring_show_fdinfo() iterates over pending SQEs and, for 128-byte SQEs on an IORING_SETUP_SQE_MIXED ring, needs to detect when the second half of the SQE would be past the end of the sq_sqes array. The current check tests (++sq_head & sq_mask) == 0, but sq_head is only incremented when a 128-byte SQE is encountered, not on every iteration. The actual array index is sq_idx = (i + sq_head) & sq_mask, which can be sq_mask (the last slot) while the wrap check passes. Fix by checking sq_idx directly. Keep the sq_head increment so the loop still skips the second half of the 128-byte SQE on the next iteration.
How severe is CVE-2026-31484?
CVE-2026-31484 has a CVSS score of 7.1/10 (HIGH severity). The EPSS model estimates a 0.12% probability of exploitation in the next 30 days.
How do I fix CVE-2026-31484?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2026-31484?

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Source: NVD / NIST