CVE-2026-53288

MEDIUMCVSS 5.5/10EPSS 0.17%

Last modified

CVE-2026-53288 is a medium-severity vulnerability rated 5.5/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: arm64: Reserve an extra page for early kernel mapping The final part of [data, end) segment may overflow into the next page of init_pg_end[1] which is the gap page before early_init_stack[2]: [1] crash_arm64_v9.0.1> vtop ffffffed00601000 VIRTUAL PHYSICAL ffffffed00601000 83401000 PAGE DIRECTORY: ffffffecffd62000 PGD: ffffffecffd62da0 => 10000000833fb003 PMD: ffffff80033fb018 => 10000000833fe003 PTE: ffffff80033fe008 => 68000083401f03 PAGE: 83401000 PTE PHYSICAL FLAGS 68000083401f03 83401000 (VALID|SHARED|AF|NG|PXN|UXN) PAGE PHYSICAL MAPPING INDEX CNT FLAGS fffffffec00d0040 83401000 0 0 1 4000 reserved [2] ffffffed002c8000 (r) __pi__data ffffffed0054e000 (d) __pi___bss_start ffffffed005f5000 (b) __pi_init_pg_dir ffffffed005fe000 (b) __pi_init_pg_end ffffffed005ff000 (B) early_init_stack ffffffed00608000 (b) __pi__end For 4K pages, the early kernel mapping may use 2MB block entries but the kernel segments are only 64KB aligned. Segment boundaries that fall within a 2MB block therefore require a PTE table so that different attributes can be applied on either side of the boundary. KERNEL_SEGMENT_COUNT still correctly counts the five permanent kernel VMAs registered by declare_kernel_vmas(). EPSS estimates a 0.17% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: arm64: Reserve an extra page for early kernel mapping The final part of [data, end) segment may overflow into the next page of init_pg_end[1] which is the gap page before early_init_stack[2]: [1] crash_arm64_v9.0.1> vtop ffffffed00601000 VIRTUAL PHYSICAL ffffffed00601000 83401000 PAGE DIRECTORY: ffffffecffd62000 PGD: ffffffecffd62da0 => 10000000833fb003 PMD: ffffff80033fb018 => 10000000833fe003 PTE: ffffff80033fe008 => 68000083401f03 PAGE: 83401000 PTE PHYSICAL FLAGS 68000083401f03 83401000 (VALID|SHARED|AF|NG|PXN|UXN) PAGE PHYSICAL MAPPING INDEX CNT FLAGS fffffffec00d0040 83401000 0 0 1 4000 reserved [2] ffffffed002c8000 (r) __pi__data ffffffed0054e000 (d) __pi___bss_start ffffffed005f5000 (b) __pi_init_pg_dir ffffffed005fe000 (b) __pi_init_pg_end ffffffed005ff000 (B) early_init_stack ffffffed00608000 (b) __pi__end For 4K pages, the early kernel mapping may use 2MB block entries but the kernel segments are only 64KB aligned. Segment boundaries that fall within a 2MB block therefore require a PTE table so that different attributes can be applied on either side of the boundary. KERNEL_SEGMENT_COUNT still correctly counts the five permanent kernel VMAs registered by declare_kernel_vmas(). However, since commit 5973a62efa34 ("arm64: map [_text, _stext) virtual address range non-executable+read-only"), the early mapper also maps [_text, _stext) separately from [_stext, _etext). This adds one more early-only split and can require one more page-table page than the existing EARLY_SEGMENT_EXTRA_PAGES allowance reserves. Increase the 4K-page early mapping allowance by one page to cover that additional split. [catalin.marinas@arm.com: rewrote part of the commit log] [catalin.marinas@arm.com: expanded the code comment]

Metrics

CVSS 3.1
5.5/10

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

EPSS Probability
0.17%

6.4th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 6.12.54, < 6.12.91
LinuxLinux Kernel>= 6.17.4, < 6.18.33
LinuxLinux Kernel>= 6.19, < 7.0.10
LinuxLinux Kernel7.1Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-53288?
In the Linux kernel, the following vulnerability has been resolved: arm64: Reserve an extra page for early kernel mapping The final part of [data, end) segment may overflow into the next page of init_pg_end[1] which is the gap page before early_init_stack[2]: [1] crash_arm64_v9.0.1> vtop ffffffed00601000 VIRTUAL PHYSICAL ffffffed00601000 83401000 PAGE DIRECTORY: ffffffecffd62000 PGD: ffffffecffd62da0 => 10000000833fb003 PMD: ffffff80033fb018 => 10000000833fe003 PTE: ffffff80033fe008 => 68000083401f03 PAGE: 83401000 PTE PHYSICAL FLAGS 68000083401f03 83401000 (VALID|SHARED|AF|NG|PXN|UXN) PAGE PHYSICAL MAPPING INDEX CNT FLAGS fffffffec00d0040 83401000 0 0 1 4000 reserved [2] ffffffed002c8000 (r) __pi__data ffffffed0054e000 (d) __pi___bss_start ffffffed005f5000 (b) __pi_init_pg_dir ffffffed005fe000 (b) __pi_init_pg_end ffffffed005ff000 (B) early_init_stack ffffffed00608000 (b) __pi__end For 4K pages, the early kernel mapping may use 2MB block entries but the kernel segments are only 64KB aligned. Segment boundaries that fall within a 2MB block therefore require a PTE table so that different attributes can be applied on either side of the boundary. KERNEL_SEGMENT_COUNT still correctly counts the five permanent kernel VMAs registered by declare_kernel_vmas(). However, since commit 5973a62efa34 ("arm64: map [_text, _stext) virtual address range non-executable+read-only"), the early mapper also maps [_text, _stext) separately from [_stext, _etext). This adds one more early-only split and can require one more page-table page than the existing EARLY_SEGMENT_EXTRA_PAGES allowance reserves. Increase the 4K-page early mapping allowance by one page to cover that additional split. [catalin.marinas@arm.com: rewrote part of the commit log] [catalin.marinas@arm.com: expanded the code comment]
How severe is CVE-2026-53288?
CVE-2026-53288 has a CVSS score of 5.5/10 (MEDIUM severity). The EPSS model estimates a 0.17% probability of exploitation in the next 30 days.
How do I fix CVE-2026-53288?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST