Out-of-bounds write in Linux kernel
Priority LOW 31CWE-787Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · High · High
- Fix status
- Fixed
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
A flaw was found in the Linux kernel in versions before 5.12. The value of internal.ndata, in the KVM API, is mapped to an array index, which can be updated by a user process at anytime which could lead to an out-of-bounds write. The highest threat from this vulnerability is to data integrity and system availability.
Why it matters now
EPSS 0.00377 31st percentileScored 2026-11-07
Fix Fixed kernel (Linux): 5.10.32, 5.11.16Red Hat: 4 advisories
SSVC decision points
Not available: CISA has not published SSVC decision points for this record.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | kernel | 5.9 to before 5.10.32; 5.11 to before 5.11.16 | 5.10.32, 5.11.16 | Patch available | CNA |
- kernel VendorLinux Affected 5.9 to before 5.10.32; 5.11 to before 5.11.16 Fixed in 5.10.32, 5.11.16 Patch available CNA
CPE configurations NVD · 28
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 5.12 | Vulnerable | Linux |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_real_time:8:*:*:*:*:*:*:* | 8 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv:8:*:*:*:*:*:*:* | 8 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv_tus:8.4:*:*:*:*:*:*:* | 8.4 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux_for_real_time_tus:8.4:*:*:*:*:*:*:* | 8.4 | Vulnerable | Red Hat |
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* | 33 | Vulnerable | Fedoraproject |
| cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:* | 4.0 | Vulnerable | Red Hat |
| cpe:2.3:a:redhat:virtualization_host:4.0:*:*:*:*:*:*:* | 4.0 | Vulnerable | Red Hat |
| cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* | 8.0 | Running on | Red Hat |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 5.12 Vulnerable ·Linux
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_real_time:8:*:*:*:*:*:*:* Versions 8 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv:8:*:*:*:*:*:*:* Versions 8 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_real_time_for_nfv_tus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux_for_real_time_tus:8.4:*:*:*:*:*:*:* Versions 8.4 Vulnerable ·Red Hat
- cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* Versions 33 Vulnerable ·Fedoraproject
- cpe:2.3:a:redhat:virtualization:4.0:*:*:*:*:*:*:* Versions 4.0 Vulnerable ·Red Hat
- cpe:2.3:a:redhat:virtualization_host:4.0:*:*:*:*:*:*:* Versions 4.0 Vulnerable ·Red Hat
- cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:* Versions 8.0 Running on ·Red Hat
Show 18 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h700s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h300e_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h300e:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h500e_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h500e:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h700e_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h700e:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h410s:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
| cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:* | not specified by NVD | Vulnerable | NetApp |
| cpe:2.3:h:netapp:h410c:-:*:*:*:*:*:*:* | not specified by NVD | Running on | NetApp |
- cpe:2.3:a:netapp:cloud_backup:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:o:netapp:solidfire_baseboard_management_controller_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:o:netapp:h300s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h300s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h500s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h500s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h700s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h700s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h300e_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h300e:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h500e_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h500e:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h700e_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h700e:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h410s_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h410s:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
- cpe:2.3:o:netapp:h410c_firmware:-:*:*:*:*:*:*:* Versions not specified by NVD Vulnerable ·NetApp
- cpe:2.3:h:netapp:h410c:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·NetApp
Remediation
- Fix · CNA kernel (Linux) Fixed in 5.10.32, 5.11.16
Red Hat 4 advisories
- RHSA-2021:2522 Released 2021-06-22 · Red Hat rating ImportantRed Hat Virtualization Host security update [ovirt-4.4.6]
- Red Hat Virtualization 4 Hypervisor for RHEL 8 redhat-virtualization-host-4.4.6-20210615.0.el8_4, redhat-virtualization-host-image-update-4.4.6-20210615.0.el8_4
- RHSA-2021:2168 Released 2021-06-01 · Red Hat rating Importantkernel security and bug fix update
- Red Hat CodeReady Linux Builder (v. 8) kernel-tools-libs-devel-4.18.0-305.3.1.el8_4
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-305.3.1.el8_4, kernel-4.18.0-305.3.1.el8_4, kernel-abi-stablelists-4.18.0-305.3.1.el8_4 +19
- RHSA-2021:2165 Released 2021-06-01 · Red Hat rating Importantkpatch-patch security update
- Red Hat Enterprise Linux BaseOS (v. 8) kpatch-patch-4_18_0-305-1-1.el8
Show 1 more Red Hat advisories
- RHSA-2021:2169 Released 2021-06-01 · Red Hat rating Importantkernel-rt security and bug fix update
- Red Hat Enterprise Linux Real Time (v. 8) kernel-rt-4.18.0-305.3.1.rt7.75.el8_4, kernel-rt-core-4.18.0-305.3.1.rt7.75.el8_4, kernel-rt-debug-4.18.0-305.3.1.rt7.75.el8_4 +7
- Red Hat Enterprise Linux Real Time for NFV (v. 8) kernel-rt-4.18.0-305.3.1.rt7.75.el8_4, kernel-rt-core-4.18.0-305.3.1.rt7.75.el8_4, kernel-rt-debug-4.18.0-305.3.1.rt7.75.el8_4 +9
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat CodeReady Linux Builder (v. 8) | Fixed | RHSA-2021:2168 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2021:2165, RHSA-2021:2168 |
| Red Hat Enterprise Linux Real Time (v. 8) | Fixed | RHSA-2021:2169 |
| Red Hat Enterprise Linux Real Time for NFV (v. 8) | Fixed | RHSA-2021:2169 |
| Red Hat Virtualization 4 Hypervisor for RHEL 8 | Fixed | RHSA-2021:2522 |
Not affected: 5 products
- RHEL 8-based RHEV-H for RHEV 4 (build requirements)
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-3501
- 2026-10-03 Alias added: GHSA-hvwc-6fg8-r6p5
References
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2021-3501 · CVE Program
- CVE-2021-3501 · NVD
- FIRST EPSS
- GHSA-hvwc-6fg8-r6p5 · GitHub Advisory Database · CC BY 4.0
- CVE-2021-3501 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences