CVE-2026-89489 (CVSS 7.8)

Description

In the Linux kernel, the following vulnerability has been resolved: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [[email protected]: fix comment style]

Is your site exposed to CVE-2026-89489?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

7.8

HIGH

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

EPSS — Exploit Prediction

0.0014

Probability of exploitation

0.03%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

References

Other References

https://git.kernel.org/stable/c/1f2e92e499d863f81df1732af59b4a3559969193 https://git.kernel.org/stable/c/497cba0b02e5555d99fe9ee1dc478af743ab7f7a https://git.kernel.org/stable/c/574ae2ac2b314aa33498cd2c28add106cbe644f2 https://git.kernel.org/stable/c/78004e9a87f240df03e2f73120d291763c32e0a7 https://git.kernel.org/stable/c/a520e8cac54fb403f3800125b606f55fcad42cb9 https://git.kernel.org/stable/c/b53435c079c78f89f70a62dd5a322cca4e292b34 https://git.kernel.org/stable/c/bf310718c6fa6adeee06d207a55489546d860e2c https://git.kernel.org/stable/c/d64a75369cd0f2ee79afcc9d9ca34a3890989379

Frequently Asked Questions

What is CVE-2026-89489? +

In the Linux kernel, the following vulnerability has been resolved: openrisc: fix arbitrary kernel memory access via or1k_atomic syscall sys_or1k_atomic() (syscall 244 in the "or1k" ABI) takes two user pointers, v1 and v2, and swaps the words they point to in hand-written assembly. l.lwz r29,0(r4) l.lwz r27,0(r5) l.sw 0(r4),r27 l.sw 0(r5),r29 The pointers are not checked with access_ok(). The four memory accesses also have no exception table entries. A caller passes a kernel address as either pointer, and the syscall reads from and writes to it directly. This gives an unprivileged process a kernel read/write primitive. It overwrites kernel data such as the sys_call_table, gaining code execution in kernel context. Check both pointers before entering the critical section. Add fixups for the four memory accesses so faults on valid but unmapped user addresses return -EFAULT. [[email protected]: fix comment style] It has a CVSS v3.1 base score of 7.8 (HIGH).

How severe is CVE-2026-89489? +

CVE-2026-89489 has a CVSS v3.1 score of 7.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0014, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-89489? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

CVE-2026-89489