Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1336 CNY

100%
Buy Us a Coffee

CVE-2026-79603— Unconditionally do TLB flushing ahead of page scrubbing

Quick assessment

Affected
Xen Xen
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Xen是Xen组织开源的一款开源的虚拟机监视器产品。该产品能够使不同和不兼容的操作系统运行在同一台计算机上,并支持在运行时进行迁移,保证正常运行并且避免宕机。 Xen存在资源管理错误漏洞，该漏洞源于x86 PV客户机释放内存页后仍保留过时的TLB条目，导致仅在页面被重新使用时才执行TLB刷新，且页面可能在刷新前被擦除，存在允许PV客户机修改已擦除页面的窗口期。

AI Predicted 5.3 Difficulty: Hard EPSS 0.23% · P14

Possible ATT&CK Techniques 1 AI

T1620 · Reflective Code Loading

Affected Version Matrix 1

VendorProduct Version RangeStatus
Xen Xen consult Xen advisory XSA-511 unknown
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-79603

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
Unconditionally do TLB flushing ahead of page scrubbing
Source: CVE Program / CVE List V5
Vulnerability Description
x86 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.
Source: CVE Program / CVE List V5
CVSS Information
N/A
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Xen 资源管理错误漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Xen是Xen组织开源的一款开源的虚拟机监视器产品。该产品能够使不同和不兼容的操作系统运行在同一台计算机上,并支持在运行时进行迁移,保证正常运行并且避免宕机。 Xen存在资源管理错误漏洞，该漏洞源于x86 PV客户机释放内存页后仍保留过时的TLB条目，导致仅在页面被重新使用时才执行TLB刷新，且页面可能在刷新前被擦除，存在允许PV客户机修改已擦除页面的窗口期。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Xen Xen consult Xen advisory XSA-511 -

II. Public POCs for CVE-2026-79603

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-79603

请登录查看更多情报信息。

Vendor Advisories for CVE-2026-79603 (1)

Same Patch Batch · Xen · 2026-09-08 · 3 CVEs total

CVE-2026-62437 x86: DMs may cause mem leak by IRQ binding
CVE-2026-79602 x86: improper handling of HVM emulation return codes

IV. Related Vulnerabilities

Same product: Xen
Same vendor: Xen

V. Comments for CVE-2026-79603

No comments yet

Leave a comment