Linux Kernel up to 6.12.108/6.18.49/7.2.3 OpenRISC sys_or1k_atomic v1/v2 out-of-bounds write

CVSS Meta Temp Score
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CTI Interest Score
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8.4$0-$5k0.00+

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. It has been rated as very critical. This issue affects the function sys_or1k_atomic of the component OpenRISC. This manipulation of the argument v1/v2 causes out-of-bounds write. This vulnerability appears as CVE-2026-89489. The attack requires local access. There is no available exploit. Upgrading the affected component is advised.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.108/6.18.49/7.2.3. It has been declared as very critical. Affected by this vulnerability is the function sys_or1k_atomic of the component OpenRISC. The manipulation of the argument v1/v2 with an unknown input leads to a out-of-bounds write vulnerability. The CWE definition for the vulnerability is CWE-787. The product writes data past the end, or before the beginning, of the intended buffer. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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 is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-89489 since 09/11/2026. The exploitation appears to be easy. Attacking locally is a requirement. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/11/2026).

Upgrading to version 6.12.109, 6.18.50, 7.2.4 or 7.3-rc1 eliminates this vulnerability. Applying the patch a520e8cac54fb403f3800125b606f55fcad42cb9/d64a75369cd0f2ee79afcc9d9ca34a3890989379/b53435c079c78f89f70a62dd5a322cca4e292b34/78004e9a87f240df03e2f73120d291763c32e0a7 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.8
VulDB Meta Temp Score: 8.4

VulDB Base Score: 8.8
VulDB Temp Score: 8.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Out-of-bounds write
CWE: CWE-787 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.109/6.18.50/7.2.4/7.3-rc1
Patch: a520e8cac54fb403f3800125b606f55fcad42cb9/d64a75369cd0f2ee79afcc9d9ca34a3890989379/b53435c079c78f89f70a62dd5a322cca4e292b34/78004e9a87f240df03e2f73120d291763c32e0a7

Timelineinfo

09/11/2026 Advisory disclosed
09/11/2026 +0 days CVE reserved
09/11/2026 +0 days VulDB entry created
09/11/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89489 (🔒)
GCVE (CVE): GCVE-0-2026-89489
GCVE (VulDB): GCVE-100-402703

Entryinfo

Created: 09/11/2026 23:49
Changes: 09/11/2026 23:49 (60)
Complete: 🔍
Cache ID: 216::103

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