What is CVE-2026-90423?

CVE-2026-90423 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10, affecting Linux kernel versions from 6.15 onward and patched in 6.18.52, 7.2.6 and 7.3-rc1. CVE-2026-90423 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

What is the CVSS score for CVE-2026-90423?

CVE-2026-90423 has a CVSS score of 7.8 out of 10, rated High severity. The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

Is there a patch available for CVE-2026-90423?

Yes, CVE-2026-90423 has been patched. Fixed versions include 6.18.52, 7.2.6 and 7.3-rc1. If you are running Linux kernel 6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.

Is CVE-2026-90423 actively exploited?

CVE-2026-90423 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

CVE-2026-90423

High

In the Linux kernel, the following vulnerability has been resolved: RDMA/rxe: Fix UAF in ODP init error-handling path rxe_odp_mr_init_user() stores &umem_odp->umem in mr->umem before calling rxe_odp_init_pages(). If rxe_odp_init_pages() fails, rxe_odp_mr_init_user() releases umem_odp and returns an error. rxe_reg_user_mr() then unwinds the error through rxe_cleanup(), rxe_mr_cleanup(), ib_umem_release(mr->umem). There is an IS_ERR_OR_NULL(umem) check at the start of ib_umem_release(). But since mr->umem is NOT reset to NULL in the error handling path of rxe_odp_mr_init_user(), the check passes and it reads already-freed fields like umem->is_dmabuf, causing UAF. Fix the UAF by clearing mr->umem after releasing the failed ODP umem so the MR cleanup path does not release it again.

Package Linux Kernel

Published 2026-09-17

Last modified 2026-09-18

CVSS version 3.1

Patch available

Yes

CVSS 3.1 score

7.8

out of 10

High

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Vector string

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

Affected versions

Linux kernel versions 6.15 and later are affected. Fixed in 6.18.52, 7.2.6, 7.3-rc1 and their respective stable series.

Affected from

≥ 6.15

Fixed in

✓ 6.18.52 6.18.x ✓ 7.2.6 7.2.x ✓ 7.3-rc1

References

3 total

Details

CVE ID CVE-2026-90423

Severity High

CVSS score 7.8 / 10

CVSS version 3.1

Published 2026-09-17

Modified 2026-09-18

KEV No

Patch

Yes

Package linux

Frequently asked questions

What is CVE-2026-90423?

CVE-2026-90423 is a High severity Linux kernel vulnerability with a CVSS score of 7.8 out of 10 . It affects Linux kernel versions from 6.15 onward and has been patched in 6.18.52, 7.2.6 and 7.3-rc1. CVE-2026-90423 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
What is the CVSS score for CVE-2026-90423?

CVE-2026-90423 has a CVSS score of 7.8 out of 10, rated High severity (CVSS 3.1). The vector string is CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.
Is there a patch available for CVE-2026-90423?

Yes. CVE-2026-90423 has been patched. Fixed versions include 6.18.52, 7.2.6 and 7.3-rc1. If you are running Linux kernel 6.15 or later up to the fix versions, apply the relevant patch for your kernel branch.
Is CVE-2026-90423 actively exploited?

No. CVE-2026-90423 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.