CVE-2022-26362
CVE-2022-26362 is a medium-severity vulnerability in Xen with a CVSS 3.x base score of 6.4. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-362.
Key facts
- Severity: Medium (CVSS 3.x base score 6.4)
- CVSS v2: 6.9
- EPSS exploit prediction: 0% (30th percentile)
- Actively exploited: Not listed in CISA KEV
- Weakness: CWE-362
- Affected product: Xen
- Published:
- Last modified:
Description
x86 pv: Race condition in typeref acquisition Xen maintains a type reference count for pages, in addition to a regular reference count. This scheme is used to maintain invariants required for Xen's safety, e.g. PV guests may not have direct writeable access to pagetables; updates need auditing by Xen. Unfortunately, the logic for acquiring a type reference has a race condition, whereby a safely TLB flush is issued too early and creates a window where the guest can re-establish the read/write mapping before writeability is prohibited.
Frequently asked questions
- What is CVE-2022-26362?
- x86 pv: Race condition in typeref acquisition Xen maintains a type reference count for pages, in addition to a regular reference count. This scheme is used to maintain invariants required for Xen's safety, e.g. PV guests may not have direct writeable access to pagetables; updates need auditing by Xen. Unfortunately, the logic for acquiring a type reference has a race condition, whereby a safely TLB flush is issued too early and creates a window where the guest can re-establish the read/write mapping before writeability is prohibited.
- How severe is CVE-2022-26362?
- CVE-2022-26362 has a CVSS 3.x base score of 6.4, rated medium severity. It is exploitable over local access with high attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
- Is CVE-2022-26362 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (30th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2022-26362?
- CVE-2022-26362 primarily affects Xen. In total, 4 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2022-26362?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- When was CVE-2022-26362 published?
- CVE-2022-26362 was published on 2022-06-09 and last updated on 2026-06-17.
References
- http://packetstormsecurity.com/files/167718/Xen-TLB-Flush-Bypass.html
- http://www.openwall.com/lists/oss-security/2022/06/09/3
- http://xenbits.xen.org/xsa/advisory-401.html
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OH65U6FTTB5MLH5A6Q3TW7KVCGOG4MYI/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RKRXZ4LHGCGMOG24ZCEJNY6R2BTS4S2Q/
- https://security.gentoo.org/glsa/202208-23
- https://www.debian.org/security/2022/dsa-5184
- https://xenbits.xenproject.org/xsa/advisory-401.txt
Affected products (4)
- cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:*
- cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*
- cpe:2.3:o:fedoraproject:fedora:36:*:*:*:*:*:*:*
- cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*
More vulnerabilities in Xen
- CVE-2017-10921 — Critical (CVSS 10.0): The grant-table feature in Xen through 4.8.x does not ensure sufficient type counts for a GNTMAP_device_map and…
- CVE-2017-10920 — Critical (CVSS 10.0): The grant-table feature in Xen through 4.8.x mishandles a GNTMAP_device_map and GNTMAP_host_map mapping, when followed…
- CVE-2017-10918 — Critical (CVSS 10.0): Xen through 4.8.x does not validate memory allocations during certain P2M operations, which allows guest OS users to…
- CVE-2017-10912 — Critical (CVSS 10.0): Xen through 4.8.x mishandles page transfer, which allows guest OS users to obtain privileged host OS access, aka…
- CVE-2015-8104 — Critical (CVSS 10.0): The KVM subsystem in the Linux kernel through 4.2.6, and Xen 4.3.x through 4.6.x, allows guest OS users to cause a…
- CVE-2018-12892 — Critical (CVSS 9.9): An issue was discovered in Xen 4.7 through 4.10.x. libxl fails to pass the readonly flag to qemu when setting up a SCSI…
Other CWE-362 (Race Condition) vulnerabilities
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- CVE-2015-8556 — Critical (CVSS 10.0): Local privilege escalation vulnerability in the Gentoo QEMU package before 2.5.0-r1.
- CVE-2014-0703 — Critical (CVSS 10.0): Cisco Wireless LAN Controller (WLC) devices 7.4 before 7.4.110.0 distribute Aironet IOS software with a race condition…
- CVE-2010-1228 — Critical (CVSS 10.0): Multiple race conditions in the sandbox infrastructure in Google Chrome before 4.1.249.1036 have unspecified impact and…
- CVE-2008-6598 — Critical (CVSS 10.0): Multiple race conditions in WANPIPE before 3.3.6 have unknown impact and attack vectors related to "bri restart logic."
- CVE-2026-46137 — Critical (CVSS 9.8): In the Linux kernel, the following vulnerability has been resolved: mptcp: pm: ADD_ADDR rtx: fix potential…