Xen
Vulnerability activity for Xen: what is being exploited, what was published lately, and when the next patch release is due.
Last 30 days
- CVEs
- 10
- Critical (CVSS 9+)
- 1
- Exploited (CISA KEV)
- 0
- With exploit code
- 0
Last 90 days
- CVEs
- 13
- Critical (CVSS 9+)
- 1
- Exploited (CISA KEV)
- 0
- With exploit code
- 0
Last 365 days
- CVEs
- 19
- Critical (CVSS 9+)
- 1
- Exploited (CISA KEV)
- 0
- With exploit code
- 0
Exploited now
None of this vendor's CVEs are on CISA's known-exploited list.
Recent
- 4.4MediumNov 4, 2026XenCVE-2026-102704[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] A common access pattern is a batch of Grant Copy operations acting on adjacent address ranges in the same source or destination page. For performance reasons, Xen caches details internally to reuse already validated data. The conditions on when to re-validate the internal data were not correct in some cases: - Frame numbers and grant references could wrongly be mi
- 4.4MediumNov 4, 2026XenCVE-2026-102703[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] A common access pattern is a batch of Grant Copy operations acting on adjacent address ranges in the same source or destination page. For performance reasons, Xen caches details internally to reuse already validated data. The conditions on when to re-validate the internal data were not correct in some cases: - Frame numbers and grant references could wrongly be mi
- 5.5MediumOct 13, 2026Xen Memory corruptionCVE-2026-79611For XSA-308 logic was introduced, as VMX VMEntry checks do not like the exact combination of state which occurs when #DB in intercepted, Single Stepping is active, and blocked by STI/MovSS is active, despite this being a legitimate state to be in. The resulting VMEntry failure is fatal to the guest. Sadly there is another special sub-case of the above, with branch tracing enabled. In that case the prior adjustment would still cause a VMentry failure, as before fatal to the guest.
- 8.8HighOct 13, 2026Xen Auth bypass / access controlCVE-2026-79609XPTI (Xen Page Table Isolation) was introduced to mitigate Meltdown (CVE-2017-5754, one aspect of XSA-254). This involves copying 64-bit PV guest page table entries from guest-chosen root page tables to the Xen- chosen one which is in actual use by hardware. To read the guest root page table, the directmap is used. PV guests, however, have a directmap which may not cover all memory; in particular this is the case if any memory extends beyond the 5 TiB (CONFIG_BIGMEM=y: 3.5 TiB) address bounda
- 9.8CriticalOct 13, 2026XenCVE-2026-79608The workaround for XSA-433 (Zenbleed, CVE-2023-20593) was later re-worked to better integrate with other manipulations of the same MSR. In this rework an inverted conditional was introduced, resulting in the workaround to not be applied when needed and vice versa. For more details, see: http://xenbits.xen.org/xsa/advisory-433.html
- 5.5MediumOct 13, 2026Xen Memory corruptionCVE-2026-79607During Xenstore live update the state record for a Xenstore watch with specified watch depth is written with two bytes missing. This results in an inconsistent state when reading the state back in the new Xenstore, causing a crash of Xenstore or wrong Xenstore data.
- 7.5HighOct 13, 2026Xen Memory corruptionCVE-2026-102702[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] 1) XSA-437 (CVE-2023-34321) addressed issues with overflows in calculations involved in guests flushing caches through GNTTABOP_cache_flush. Unfortunately the fix there introduced a calculation which may underflow, resulting in a loop which would - at least on 64-bit Arm - take excessively long, and which would likely eventually crash the hypervisor.
- 7.5HighOct 13, 2026Xen Memory corruptionCVE-2026-102699[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] 1) XSA-437 (CVE-2023-34321) addressed issues with overflows in calculations involved in guests flushing caches through GNTTABOP_cache_flush. Unfortunately the fix there introduced a calculation which may underflow, resulting in a loop which would - at least on 64-bit Arm - take excessively long, and which would likely eventually crash the hypervisor.
- 4.7MediumOct 13, 2026Xen Denial of serviceCVE-2026-102700With its original introduction, GNTTAB_cache_flush was made available uniformly. XSA-232 (CVE-2017-14318) then covered an omitted NULL pointer check, yet the addition of that check failed to adjust the subsequent error path. That error path fails to drop a page reference in case the specified page
- 8.8HighOct 13, 2026XenCVE-2026-79610XSA-501 was about issues with v1 -> v2 and v2 -> v1 changes racing certain other grant table operations. Sadly a v2 -> v1 -> v2 change has yet another effect which wasn't accounted for: During the first change, status pages would be freed. During the second change they would be allocated again. H
- 4.3MediumSep 8, 2026XenCVE-2026-79603x86 PV guests can free memory pages while still keeping a stale TLB entry pointing to them. A TLB flush is only issued by Xen (if needed) when the page is re-used. Since it's possible for the page to be scrubbed ahead of the TLB flush, there's a window where a PV guest can modify an already scrubbed page.
- 8.8HighSep 8, 2026Xen Memory corruptionCVE-2026-79602A guest with a PCI device assigned that has at least a BAR on the IO port space can trigger a BUG() in Xen.
- 6.5MediumSep 8, 2026XenCVE-2026-62437When guests are terminated, various pieces of cleanup need carrying out. The cleaning up of PCI devices which were assigned to guests, and the associated removal of tracking structures for IRQs used by the devices occurs relatively early in the process. Unfortunately after that point the guest about to be terminated could cause its device model (DM) to re-establish such tracking structures, by having it bind one or more IRQs anew. While some of those tracking structures would still be cleaned
- 7.8HighMay 19, 2026xenCVE-2026-23558The adjustments made for XSA-379 as well as those subsequently becoming XSA-387 still left a race window, when a HVM or PVH guest does a grant table version change from v2 to v1 in parallel with mapping the status page(s) via XENMEM_add_to_physmap. Some of the status pages may then be freed while mappings of them would still be inserted into the guest's secondary (P2M) page tables.
- 6.5MediumMay 19, 2026xenCVE-2026-23557Any guest can cause xenstored to crash by issuing a XS_RESET_WATCHES command within a transaction due to an assert() triggering. In case xenstored was built with NDEBUG #defined nothing bad will happen, as assert() is doing nothing in this case. Note that the default is not to define NDEBUG for xenstored builds even in release builds of Xen.
- 7.1HighMar 23, 2026xenCVE-2026-23555Any guest issuing a Xenstore command accessing a node using the (illegal) node path "/local/domain/", will crash xenstored due to a clobbered error indicator in xenstored when verifying the node path. Note that the crash is forced via a failing assert() statement in xenstored. In case xenstored is being built with NDEBUG #defined, an unprivileged guest trying to access the node path "/local/domain/" will result in it no longer being serviced by xenstored, other guests (including dom0) will stil
- 7.8HighMar 23, 2026xenCVE-2026-23554The Intel EPT paging code uses an optimization to defer flushing of any cached EPT state until the p2m lock is dropped, so that multiple modifications done under the same locked region only issue a single flush. Freeing of paging structures however is not deferred until the flushing is done, and can result in freed pages transiently being present in cached state. Such stale entries can point to memory ranges not owned by the guest, thus allowing access to unintended memory regions.
- 2.9LowJan 28, 2026xenCVE-2026-23553In the context switch logic Xen attempts to skip an IBPB in the case of a vCPU returning to a CPU on which it was the previous vCPU to run. While safe for Xen's isolation between vCPUs, this prevents the guest kernel correctly isolating between tasks. Consider: 1) vCPU runs on CPU A, running task 1. 2) vCPU moves to CPU B, idle gets scheduled on A. Xen skips IBPB. 3) On CPU B, guest kernel switches from task 1 to 2, issuing IBPB. 4) vCPU moves back to CPU A. Xen skips IBPB again. Now, t
- 8.8HighJan 28, 2026xen Memory corruptionCVE-2025-58150Shadow mode tracing code uses a set of per-CPU variables to avoid cumbersome parameter passing. Some of these variables are written to with guest controlled data, of guest controllable size. That size can be larger than the variable, and bounding of the writes was missing.
Top products
- Xen19 CVEs in the last year, 1 critical
Advisories
Official advisories from the last 90 days that name this vendor's CVEs.
- oss-security · Nov 3, 2026Xen Security Advisory 523 v2 (CVE-2026-102703,CVE-2026-102704) - arbitrary read/write via grant copyCVE-2026-102703CVE-2026-102704
- CCCS (Canada) · Oct 13, 2026Citrix security advisory (AV26-1034)CVE-2026-102700CVE-2026-79610
Counts cover CVEs and advisories Watch Floor tracks, by the date they became news. Updated every 10 minutes.