What’s Vulnerable › Vulnerabilities

CVE-2026-90323: ublk: validate auto buf reg before taking uring_cmd

• Severity: unknown
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-09-17 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: ublk: validate auto buf reg before taking uring_cmd With UBLK_F_AUTO_BUF_REG, invalid sqe->addr can fail after ublk_fill_io_cmd() has set UBLK_IO_FLAG_ACTIVE. The uring_cmd is completed while the tag stays active, which can hang teardown. Split validation from buffer apply so the check has no side effects, then take the uring_cmd and store the already-validated buffer. Apply the same order in FETCH so io->buf is not written before __ublk_fetch() state checks.

Affected products

• Linux kernel: 6.17 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/653d22269a8b83b491f7f186a5d7872f14e6ddca
• https://git.kernel.org/stable/c/8397942b67128e0b1275cfedb5abf4faafac5fd0
• https://git.kernel.org/stable/c/ca5a01eee34c7cbe0f531a613b0292a3ad1a419b

Get alerted when CVE-2026-90323 or the next vulnerability affects your stack