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TI-2026-24343 Aliases CVE-2026-31787GHSA-3c28-g28m-gm93

xen/privcmd: fix double free via VMA splitting

Priority LOW 33CWE-415Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 33 fixed, 2 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-415 and the CVSS impact.

Summary

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

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00183 7th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.254, 5.15.204, 6.1.170 +5Red Hat: 11 advisoriesRed Hat: 33 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux3.8 and later5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, 6.18.26, 7.0.3, 7.1Patch availableCNA
  • Linux VendorLinux Affected 3.8 and later Fixed in 5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, 6.18.26, 7.0.3, 7.1 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*3.8 to before 5.10.254; 5.11 to before 5.15.204; 5.16 to before 6.1.170; 6.2 to before 6.6.137; 6.7 to before 6.12.85; 6.13 to before 6.18.26; 6.19 to before 7.0.3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:*7.1 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:*7.1 rc2VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 3.8 to before 5.10.254; 5.11 to before 5.15.204; 5.16 to before 6.1.170; 6.2 to before 6.6.137; 6.7 to before 6.12.85; 6.13 to before 6.18.26; 6.19 to before 7.0.3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.10.254, 5.15.204, 6.1.170, 6.6.137, 6.12.85, 6.18.26, 7.0.3, 7.1

Red Hat 11 advisories

  • RHSA-2026:53989 Released 2026-08-12 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.6) bpftool-4.18.0-372.206.1.el8_6, kernel-4.18.0-372.206.1.el8_6, kernel-abi-stablelists-4.18.0-372.206.1.el8_6 +14
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6) bpftool-4.18.0-372.206.1.el8_6, kernel-4.18.0-372.206.1.el8_6, kernel-abi-stablelists-4.18.0-372.206.1.el8_6 +14
  • RHSA-2026:52764 Released 2026-08-10 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream EUS (v. 10.0) kernel-64k-debug-devel-6.12.0-55.95.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.95.1.el10_0, kernel-64k-devel-6.12.0-55.95.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS EUS (v. 10.0) kernel-6.12.0-55.95.1.el10_0, kernel-64k-6.12.0-55.95.1.el10_0, kernel-64k-core-6.12.0-55.95.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0) kernel-tools-libs-devel-6.12.0-55.95.1.el10_0, libperf-6.12.0-55.95.1.el10_0
    • Red Hat Enterprise Linux Real Time EUS (v. 10.0) kernel-rt-6.12.0-55.95.1.el10_0, kernel-rt-64k-6.12.0-55.95.1.el10_0, kernel-rt-64k-core-6.12.0-55.95.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0) kernel-rt-6.12.0-55.95.1.el10_0, kernel-rt-core-6.12.0-55.95.1.el10_0, kernel-rt-debug-6.12.0-55.95.1.el10_0 +11
  • RHSA-2026:52649 Released 2026-08-10 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS E4S (v.8.8) bpftool-4.18.0-477.158.1.el8_8, kernel-4.18.0-477.158.1.el8_8, kernel-abi-stablelists-4.18.0-477.158.1.el8_8 +14
    • Red Hat Enterprise Linux BaseOS TUS (v.8.8) bpftool-4.18.0-477.158.1.el8_8, kernel-4.18.0-477.158.1.el8_8, kernel-abi-stablelists-4.18.0-477.158.1.el8_8 +14
Show 8 more Red Hat advisories
  • RHSA-2026:51603 Released 2026-08-07 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream E4S (v.9.2) kernel-64k-debug-devel-5.14.0-284.186.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.186.1.el9_2, kernel-64k-devel-5.14.0-284.186.1.el9_2 +10
    • Red Hat Enterprise Linux BaseOS E4S (v.9.2) bpftool-7.0.0-284.186.1.el9_2, kernel-5.14.0-284.186.1.el9_2, kernel-64k-5.14.0-284.186.1.el9_2 +29
  • RHSA-2026:51604 Released 2026-08-07 · Red Hat rating Important
    kernel-rt security, bug fix, and enhancement update
    • Red Hat Enterprise Linux Real Time E4S (v.9.2) kernel-rt-5.14.0-284.186.1.rt14.471.el9_2, kernel-rt-core-5.14.0-284.186.1.rt14.471.el9_2, kernel-rt-debug-5.14.0-284.186.1.rt14.471.el9_2 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2) kernel-rt-5.14.0-284.186.1.rt14.471.el9_2, kernel-rt-core-5.14.0-284.186.1.rt14.471.el9_2, kernel-rt-debug-5.14.0-284.186.1.rt14.471.el9_2 +11
  • RHSA-2026:48386 Released 2026-07-31 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream E4S (v.9.4) kernel-64k-debug-devel-5.14.0-427.141.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.141.1.el9_4, kernel-64k-devel-5.14.0-427.141.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS E4S (v.9.4) bpftool-7.3.0-427.141.1.el9_4, kernel-5.14.0-427.141.1.el9_4, kernel-64k-5.14.0-427.141.1.el9_4 +29
    • Red Hat Enterprise Linux Real Time E4S (v.9.4) kernel-rt-5.14.0-427.141.1.el9_4, kernel-rt-core-5.14.0-427.141.1.el9_4, kernel-rt-debug-5.14.0-427.141.1.el9_4 +9
    • Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4) kernel-rt-5.14.0-427.141.1.el9_4, kernel-rt-core-5.14.0-427.141.1.el9_4, kernel-rt-debug-5.14.0-427.141.1.el9_4 +11
  • RHSA-2026:47248 Released 2026-07-28 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS AUS (v.8.4) bpftool-4.18.0-305.200.1.el8_4, kernel-4.18.0-305.200.1.el8_4, kernel-abi-stablelists-4.18.0-305.200.1.el8_4 +14
    • Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4) bpftool-4.18.0-305.200.1.el8_4, kernel-4.18.0-305.200.1.el8_4, kernel-abi-stablelists-4.18.0-305.200.1.el8_4 +14
  • RHSA-2026:27789 Released 2026-06-22 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.17.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.17.1.el9_8, kernel-64k-devel-5.14.0-687.17.1.el9_8 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.17.1.el9_8, kernel-64k-5.14.0-687.17.1.el9_8, kernel-64k-core-5.14.0-687.17.1.el9_8 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.17.1.el9_8, libperf-5.14.0-687.17.1.el9_8
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.17.1.el9_8, kernel-rt-64k-5.14.0-687.17.1.el9_8, kernel-rt-64k-core-5.14.0-687.17.1.el9_8 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.17.1.el9_8, kernel-rt-core-5.14.0-687.17.1.el9_8, kernel-rt-debug-5.14.0-687.17.1.el9_8 +9
  • RHSA-2026:27288 Released 2026-06-20 · Red Hat rating Important
    kernel security, bug fix, and enhancement update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.26.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.26.1.el10_2, kernel-64k-devel-6.12.0-211.26.1.el10_2 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.26.1.el10_2, kernel-64k-6.12.0-211.26.1.el10_2, kernel-64k-core-6.12.0-211.26.1.el10_2 +29
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.26.1.el10_2, libperf-6.12.0-211.26.1.el10_2
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.26.1.el10_2, kernel-rt-64k-6.12.0-211.26.1.el10_2, kernel-rt-64k-core-6.12.0-211.26.1.el10_2 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.26.1.el10_2, kernel-rt-core-6.12.0-211.26.1.el10_2, kernel-rt-debug-6.12.0-211.26.1.el10_2 +9
  • RHSA-2026:26427 Released 2026-06-16 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.134.1.el8_10, kernel-4.18.0-553.134.1.el8_10, kernel-abi-stablelists-4.18.0-553.134.1.el8_10 +19
    • Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.134.1.el8_10
  • RHSA-2026:26428 Released 2026-06-16 · Red Hat rating Important
    kernel-rt security update
    • Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.134.1.rt7.475.el8_10, kernel-rt-core-4.18.0-553.134.1.rt7.475.el8_10, kernel-rt-debug-4.18.0-553.134.1.rt7.475.el8_10 +9
    • Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.134.1.rt7.475.el8_10, kernel-rt-core-4.18.0-553.134.1.rt7.475.el8_10, kernel-rt-debug-4.18.0-553.134.1.rt7.475.el8_10 +7

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2026:27288
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2026:27789
Red Hat Enterprise Linux AppStream E4S (v.9.2)Fixed RHSA-2026:51603
Red Hat Enterprise Linux AppStream E4S (v.9.4)Fixed RHSA-2026:48386
Red Hat Enterprise Linux AppStream EUS (v. 10.0)Fixed RHSA-2026:52764
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2026:27288
Red Hat Enterprise Linux BaseOS (v. 8)Fixed RHSA-2026:26427
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2026:27789
Red Hat Enterprise Linux BaseOS AUS (v.8.4)Fixed RHSA-2026:47248
Red Hat Enterprise Linux BaseOS AUS (v.8.6)Fixed RHSA-2026:53989
Red Hat Enterprise Linux BaseOS E4S (v.8.8)Fixed RHSA-2026:52649
Red Hat Enterprise Linux BaseOS E4S (v.9.2)Fixed RHSA-2026:51603
Red Hat Enterprise Linux BaseOS E4S (v.9.4)Fixed RHSA-2026:48386
Red Hat Enterprise Linux BaseOS EUS (v. 10.0)Fixed RHSA-2026:52764
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.4)Fixed RHSA-2026:47248
Red Hat Enterprise Linux BaseOS EUS EXTENSION (v.8.6)Fixed RHSA-2026:53989
Red Hat Enterprise Linux BaseOS TUS (v.8.8)Fixed RHSA-2026:52649
Red Hat Enterprise Linux CRB (v. 8)Fixed RHSA-2026:26427
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2026:27288
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2026:27789
Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)Fixed RHSA-2026:52764
Red Hat Enterprise Linux NFV (v. 8)Fixed RHSA-2026:26428
Red Hat Enterprise Linux RT (v. 8)Fixed RHSA-2026:26428
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2026:27288
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2026:27789
Red Hat Enterprise Linux Real Time E4S (v.9.2)Fixed RHSA-2026:51604
Red Hat Enterprise Linux Real Time E4S (v.9.4)Fixed RHSA-2026:48386
Red Hat Enterprise Linux Real Time EUS (v. 10.0)Fixed RHSA-2026:52764
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2026:27288
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2026:27789
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.2)Fixed RHSA-2026:51604
Red Hat Enterprise Linux Real Time for NFV E4S (v.9.4)Fixed RHSA-2026:48386
Red Hat Enterprise Linux Real Time for NFV EUS (v. 10.0)Fixed RHSA-2026:52764
Not affected: 1 product
  • Red Hat Enterprise Linux 6

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-31787
  2. 2026-10-03 Alias added: GHSA-3c28-g28m-gm93
  3. 2026-10-29 Affected versions changed · Red Hat
  4. 2026-11-06 CISA SSVC decision points changed

References

Patch 8

Advisory 2

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences