CVE-2026-45851: Linux kernel · efi: Fix reservation of unaccepted memory table
Source GCVE Database
Not known to be exploited · CVSS 7.1 High.
Data as of 26 Oct 2026, 17:16 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 5% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 26 Oct 2026.
Description
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.
References
- nvd.nist.gov/vuln/detail/CVE-2026-45851 (opens in a new tab)
- git.kernel.org/stable/c/0862438c90487e79822d5647f854977d50381505 (opens in a new tab)
- git.kernel.org/stable/c/9b18bf59977f5c5bc3b11b210520f62500a7adf3 (opens in a new tab)
- git.kernel.org/stable/c/b7bc182ec1846be437351e44164089d988f9d0dd (opens in a new tab)
- git.kernel.org/stable/c/ba6b6f1502fa55621d1db23f253d54322bdbe4e0 (opens in a new tab)
- git.kernel.org/stable/c/e649b5916725c68f44ebf45fb396df563c5dbaf2 (opens in a new tab)