📦

xen

Vendor: xensource_inc

Actively Exploited 0 CISA KEV List
PoC / Exploits 8 Code Available
Total RCEs 22 Remote Access
Total CVEs 12 Total Indexed
Avg. EPSS 0.62% Exploit Prob.
Latest CVE CVE-2026-23558 May 19

Security Vulnerability Index

Page 2 / 2
7.5 CVSS

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] There are two issues related to the mapping of pages belonging to other domains: For one, an assertion is wrong there, where the case actually needs handling. A NULL pointer de-reference could result on a release build. This is CVE-2025-58144. And then the P2M lock isn't held until a page reference was actually obtained (or the attempt to do so has failed). Otherwise the page can not only change type, but even ownership in between, thus allowing domain boundaries to be violated. This is CVE-2025-58145.

EPSS: 0.42%
9.8 CVSS

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] There are multiple issues related to the handling and accessing of guest memory pages in the viridian code: 1. A NULL pointer dereference in the updating of the reference TSC area. This is CVE-2025-27466. 2. A NULL pointer dereference by assuming the SIM page is mapped when a synthetic timer message has to be delivered. This is CVE-2025-58142. 3. A race in the mapping of the reference TSC page, where a guest can get Xen to free a page while still present in the guest physical to machine (p2m) page tables. This is CVE-2025-58143.

EPSS: 0.34%
9.8 CVSS

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] There are multiple issues related to the handling and accessing of guest memory pages in the viridian code: 1. A NULL pointer dereference in the updating of the reference TSC area. This is CVE-2025-27466. 2. A NULL pointer dereference by assuming the SIM page is mapped when a synthetic timer message has to be delivered. This is CVE-2025-58142. 3. A race in the mapping of the reference TSC page, where a guest can get Xen to free a page while still present in the guest physical to machine (p2m) page tables. This is CVE-2025-58143.

EPSS: 0.44%
9.8 CVSS

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] There are multiple issues related to the handling and accessing of guest memory pages in the viridian code: 1. A NULL pointer dereference in the updating of the reference TSC area. This is CVE-2025-27466. 2. A NULL pointer dereference by assuming the SIM page is mapped when a synthetic timer message has to be delivered. This is CVE-2025-58142. 3. A race in the mapping of the reference TSC page, where a guest can get Xen to free a page while still present in the guest physical to machine (p2m) page tables. This is CVE-2025-58143.

EPSS: 0.44%
7.5 CVSS

When setting up interrupt remapping for legacy PCI(-X) devices, including PCI(-X) bridges, a lookup of the upstream bridge is required. This lookup, itself involving acquiring of a lock, is done in a context where acquiring that lock is unsafe. This can lead to a deadlock.

EPSS: 0.72%
4.3 CVSS

Certain instructions need intercepting and emulating by Xen. In some cases Xen emulates the instruction by replaying it, using an executable stub. Some instructions may raise an exception, which is supposed to be handled gracefully. Certain replayed instructions have additional logic to set up and recover the changes to the arithmetic flags. For replayed instructions where the flags recovery logic is used, the metadata for exception handling was incorrect, preventing Xen from handling the the exception gracefully, treating it as fatal instead.

EPSS: 0.55%
5.5 CVSS

PVH guests have their ACPI tables constructed by the toolstack. The construction involves building the tables in local memory, which are then copied into guest memory. While actually used parts of the local memory are filled in correctly, excess space that is being allocated is left with its prior contents.

EPSS: 0.30%
6.5 CVSS

The hypervisor contains code to accelerate VGA memory accesses for HVM guests, when the (virtual) VGA is in "standard" mode. Locking involved there has an unusual discipline, leaving a lock acquired past the return from the function that acquired it. This behavior results in a problem when emulating an instruction with two memory accesses, both of which touch VGA memory (plus some further constraints which aren't relevant here). When emulating the 2nd access, the lock that is already being held would be attempted to be re-acquired, resulting in a deadlock. This deadlock was already found when the code was first introduced, but was analysed incorrectly and the fix was incomplete. Analysis in light of the new finding cannot find a way to make the existing locking discipline work. In staging, this logic has all been removed because it was discovered to be accidentally disabled since Xen 4.7. Therefore, we are fixing the locking problem by backporting the removal of most of the feature. Note that even with the feature disabled, the lock would still be acquired for any accesses to the VGA MMIO region.

EPSS: 0.27%
7.3 CVSS

In x86's APIC (Advanced Programmable Interrupt Controller) architecture, error conditions are reported in a status register. Furthermore, the OS can opt to receive an interrupt when a new error occurs. It is possible to configure the error interrupt with an illegal vector, which generates an error when an error interrupt is raised. This case causes Xen to recurse through vlapic_error(). The recursion itself is bounded; errors accumulate in the the status register and only generate an interrupt when a new status bit becomes set. However, the lock protecting this state in Xen will try to be taken recursively, and deadlock.

EPSS: 0.54%
7.5 CVSS

When multiple devices share resources and one of them is to be passed through to a guest, security of the entire system and of respective guests individually cannot really be guaranteed without knowing internals of any of the involved guests. Therefore such a configuration cannot really be security-supported, yet making that explicit was so far missing. Resources the sharing of which is known to be problematic include, but are not limited to - - PCI Base Address Registers (BARs) of multiple devices mapping to the same page (4k on x86), - - INTx lines.

EPSS: 0.23%