High 7.1Published May 27, 2026

CVE-2026-45851efi: Fix reservation of unaccepted memory table

Updated under an hour ago (Oct 27, 2026, 10:00 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: efi: Fix reservation of unaccepted memory table The reserve_unaccepted() function incorrectly calculates the size of the memblock reservation for the unaccepted memory table. It aligns the size of the table, but fails to account for cases where the table's starting physical address (efi.unaccepted) is not page-aligned. If the table starts at an offset within a page and its end crosses into a subsequent page that the aligned size does not cover, the end of the table will not be reserved. This can lead to the table being overwritten or inaccessible, causing a kernel panic in accept_memory(). This issue was observed when starting Intel TDX VMs with specific memory sizes (e.g., > 64GB). Fix this by calculating the end address first (including the unaligned start) and then aligning it up, ensuring the entire range is covered by the reservation.

CVSS: 7.1 HIGH (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: May 27, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 8dbe33956d96c9d066ef15ca933ede30748198b2 before b7bc182ec1846be437351e44164089d988f9d0dd; from 8dbe33956d96c9d066ef15ca933ede30748198b2 before ba6b6f1502fa55621d1db23f253d54322bdbe4e0; from 8dbe33956d96c9d066ef15ca933ede30748198b2 before 9b18bf59977f5c5bc3b11b210520f62500a7adf3; from 8dbe33956d96c9d066ef15ca933ede30748198b2 before e649b5916725c68f44ebf45fb396df563c5dbaf2; from 8dbe33956d96c9d066ef15ca933ede30748198b2 before 0862438c90487e79822d5647f854977d50381505	CNA record
linux linux_kernel linux:linux_kernel	from 6.6.1 before 6.6.128; from 6.7 before 6.12.75; from 6.13 before 6.18.14; from 6.19 before 6.19.4; 6.6; 6.6; 6.6; 6.6; and 2 more ranges	NVD

References

References

https://git.kernel.org/stable/c/b7bc182ec1846be437351e44164089d988f9d0dd	patch
https://git.kernel.org/stable/c/ba6b6f1502fa55621d1db23f253d54322bdbe4e0	patch
https://git.kernel.org/stable/c/9b18bf59977f5c5bc3b11b210520f62500a7adf3	patch
https://git.kernel.org/stable/c/e649b5916725c68f44ebf45fb396df563c5dbaf2	patch
https://git.kernel.org/stable/c/0862438c90487e79822d5647f854977d50381505	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.