vmalloc: fix buffer overflow in vrealloc_node_align()
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 1 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-787 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: vmalloc: fix buffer overflow in vrealloc_node_align() Commit 4c5d3365882d ("mm/vmalloc: allow to set node and align in vrealloc") added the ability to force a new allocation if the current pointer is on the wrong NUMA node, or if an alignment constraint is not met, even if the user is shrinking the allocation. On this path (need_realloc), the code allocates a new object of 'size' bytes and then memcpy()s 'old_size' bytes into it. If the request is to shrink the object (size < old_size), this results in an out-of-bounds write on the new buffer. Fix this by bounding the copy length by the new allocation size.
Why it matters now
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 | Linux | 6.18 and later | 6.18.27, 7.0.4, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 6.18 and later Fixed in 6.18.27, 7.0.4, 7.1 Patch available CNA
Remediation
- Fix · CNA Linux (Linux) Fixed in 6.18.27, 7.0.4, 7.1
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
Not affected: 4 products
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux 7
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2026-46281
- 2026-10-03 Alias added: GHSA-xwpx-34xj-4qmq
References
More Linux Kernel vulnerabilities
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- 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-2026-46281 · CVE Program
- CVE-2026-46281 · NVD
- FIRST EPSS
- GHSA-xwpx-34xj-4qmq · GitHub Advisory Database · CC BY 4.0
- CVE-2026-46281 · Red Hat security data · CC BY 4.0
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