CVE-2026-52959
virt: sev-guest: Do not use host-controlled page order in cleanup path
Description
In the Linux kernel, the following vulnerability has been resolved: virt: sev-guest: Do not use host-controlled page order in cleanup path When issuing an extended guest request (SVM_VMGEXIT_EXT_GUEST_REQUEST), get_ext_report() allocates a buffer to retrieve a certificate blob from the host, keeping track of its size in report_req->certs_len. However, the host may return SNP_GUEST_VMM_ERR_INVALID_LEN, indicating an invalid buffer size, as well as the expected length of such buffer. get_ext_report() subsequently updates report_req->certs_len with the host-controlled value, and cleans up the buffer by computing a page order from such value. This is incorrect, as the host-provided length may not match the page order of the original allocation, potentially resulting in corruption in the page allocator. Fix this by using alloc_pages_exact() instead, and reusing @npages to compute the size passed to free_pages_exact(). For consistency, also use @npages to compute the size when allocating the pages, even though this last change has no functional effect.
INFO
Published Date :
June 24, 2026, 5:17 p.m.
Last Modified :
July 14, 2026, 4:28 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | HIGH | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 |
Solution
- Update the Linux kernel to the latest version.
- Apply security patches provided by the vendor.
- Rebuild and deploy the kernel.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-52959.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-52959 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-52959
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-52959 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-52959 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Jul. 14, 2026
Action Type Old Value New Value Added CWE NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:6.14:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.14:rc7:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.14:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13.8 up to (excluding) 6.14 *cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.19 up to (excluding) 7.0.10 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.14.1 up to (excluding) 6.18.33 Added Reference Type kernel.org: https://git.kernel.org/stable/c/23e6a1ca04ae44806439a5a446e62e4d42e80bb4 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/3f6fb0211b39aaa1b841260681dd02ca6b693ed5 Types: Patch Added Reference Type kernel.org: https://git.kernel.org/stable/c/9e48b4f813d2c3db75d522aa82ab705ce04b7e2d Types: Patch -
CVE Modified by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 28, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jun. 24, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3e385c0d6ce88ac9916dcf84267bd5855d830748', 'lessThan': '3f6fb0211b39aaa1b841260681dd02ca6b693ed5', 'versionType': 'git'}, {'status': 'affected', 'version': '3e385c0d6ce88ac9916dcf84267bd5855d830748', 'lessThan': '9e48b4f813d2c3db75d522aa82ab705ce04b7e2d', 'versionType': 'git'}, {'status': 'affected', 'version': '3e385c0d6ce88ac9916dcf84267bd5855d830748', 'lessThan': '23e6a1ca04ae44806439a5a446e62e4d42e80bb4', 'versionType': 'git'}, {'status': 'affected', 'version': '0b16521f95c875e79d657cb8d6911c15080dbb80', 'versionType': 'git'}, {'status': 'affected', 'version': '6.13.8', 'lessThan': '6.14', 'versionType': 'semver'}], 'programFiles': ['drivers/virt/coco/sev-guest/sev-guest.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '6.14'}, {'status': 'unaffected', 'version': '0', 'lessThan': '6.14', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.18.33', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.0.10', 'versionType': 'semver', 'lessThanOrEqual': '7.0.*'}, {'status': 'unaffected', 'version': '7.1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['drivers/virt/coco/sev-guest/sev-guest.c'], 'defaultStatus': 'affected'}] Added Description In the Linux kernel, the following vulnerability has been resolved: virt: sev-guest: Do not use host-controlled page order in cleanup path When issuing an extended guest request (SVM_VMGEXIT_EXT_GUEST_REQUEST), get_ext_report() allocates a buffer to retrieve a certificate blob from the host, keeping track of its size in report_req->certs_len. However, the host may return SNP_GUEST_VMM_ERR_INVALID_LEN, indicating an invalid buffer size, as well as the expected length of such buffer. get_ext_report() subsequently updates report_req->certs_len with the host-controlled value, and cleans up the buffer by computing a page order from such value. This is incorrect, as the host-provided length may not match the page order of the original allocation, potentially resulting in corruption in the page allocator. Fix this by using alloc_pages_exact() instead, and reusing @npages to compute the size passed to free_pages_exact(). For consistency, also use @npages to compute the size when allocating the pages, even though this last change has no functional effect. Added Reference https://git.kernel.org/stable/c/23e6a1ca04ae44806439a5a446e62e4d42e80bb4 Added Reference https://git.kernel.org/stable/c/3f6fb0211b39aaa1b841260681dd02ca6b693ed5 Added Reference https://git.kernel.org/stable/c/9e48b4f813d2c3db75d522aa82ab705ce04b7e2d