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

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-31787— xen/privcmd: fix double free via VMA splitting

Quick assessment

Affected
Linux Linux
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.

Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于xen privcmd驱动中VMA分割导致双重释放，可能导致内存损坏。

AI Predicted 5.9 Difficulty: Moderate EPSS 0.19% · P8

Possible ATT&CK Techniques 1 AI

T1203 · Exploitation for Client Execution

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux d71f513985c22f1050295d1a7e4327cf9fb060da< dbf862ce9f009128ab86b234d91413a3e450beb4 affected
d71f513985c22f1050295d1a7e4327cf9fb060da< 2b985d3a024b9e8c24e21671b34e855569763808 affected
d71f513985c22f1050295d1a7e4327cf9fb060da< 1576ff3869cbd3620717195f971c85b7d7fd62b5 affected
d71f513985c22f1050295d1a7e4327cf9fb060da< 402d84ad9e89bd4cbfd07ca8598532b7021daf95 affected
d71f513985c22f1050295d1a7e4327cf9fb060da< 2894a351fe2ea8684919d36df3188b9a35e3926f affected
d71f513985c22f1050295d1a7e4327cf9fb060da< 446ee446d9ae66f36e95c3c90bbcc4e56b94cde0 affected
d71f513985c22f1050295d1a7e4327cf9fb060da< 71bf829800758a6e3889096e4754ef47ba7fc850 affected
d71f513985c22f1050295d1a7e4327cf9fb060da< 24daca4fc07f3ff8cd0e3f629cd982187f48436a affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-31787

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Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.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
xen/privcmd: fix double free via VMA splitting
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: xen/privcmd: fix double free via VMA splitting privcmd_vm_ops defines .close (privcmd_close), but neither .may_split nor .open. When userspace does a partial munmap() on a privcmd mapping, the kernel splits the VMA via __split_vma(). Since may_split is NULL, the split is allowed. vm_area_dup() copies vm_private_data (a pages array allocated in alloc_empty_pages()) into the new VMA without any fixup, because there is no .open callback. Both VMAs now point to the same pages array. When the unmapped portion is closed, privcmd_close() calls: - xen_unmap_domain_gfn_range() - xen_free_unpopulated_pages() - kvfree(pages) The surviving VMA still holds the dangling pointer. When it is later destroyed, the same sequence runs again, which leads to a double free. Fix this issue by adding a .may_split callback denying the VMA split. This is XSA-487 / CVE-2026-31787
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
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于xen privcmd驱动中VMA分割导致双重释放，可能导致内存损坏。
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
Linux Linux d71f513985c22f1050295d1a7e4327cf9fb060da ~ dbf862ce9f009128ab86b234d91413a3e450beb4 -
Linux Linux 3.8 -

II. Public POCs for CVE-2026-31787

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

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-31787

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-31787 (8)

Same Patch Batch · Linux · 2026-04-30 · 4 CVEs total

CVE-2026-31693 7.8 HIGH cifs: some missing initializations on replay
CVE-2026-31786 7.8 HIGH Buffer overflow in drivers/xen/sys-hypervisor.c
CVE-2026-31692 rtnetlink: add missing netlink_ns_capable() check for peer netns

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-31787

No comments yet

Leave a comment