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NVD / CVE Program· CNA Linux

CVE-2026-31686: mm/kasan: fix double free for kasan pXds

HighCVSS 7.8 · v3.1—No exploit Fix available

Noroxi assessment

Priority: Monitor (action score 31/100)

  • The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
  • Probability of exploitation in the next 30 days: 0.12% (FIRST EPSS).
  • Someone with local access to the system can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Linux Linux 2277246ea265cdca64ce6fdea4b26cd6ff0ec4db, 3298bdf5a878ded06351eb293856fa84e050029e, 51d8c78be0c27ddb91bc2c0263941d8b30a47d3b.

Low priority for now. Upgrade to Linux Linux 2277246ea265cdca64ce6fdea4b26cd6ff0ec4db, 3298bdf5a878ded06351eb293856fa84e050029e, 51d8c78be0c27ddb91bc2c0263941d8b30a47d3b or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · FIRST EPSS

In the Linux kernel, the following vulnerability has been resolved: mm/kasan: fix double free for kasan pXds kasan_free_pxd() assumes the page table is always struct page aligned. But that's not always the case for all architectures. E.g. In case of powerpc with 64K pagesize, PUD table (of size 4096) comes from slab cache named pgtable-2^9. Hence instead of page_to_virt(pxd_page()) let's just directly pass the start of the pxd table which is passed as the 1st argument. This fixes the below double free kasan issue seen with PMEM: radix-mmu: Mapped 0x0000047d10000000-0x0000047f90000000 with 2.00 MiB pages ================================================================== BUG: KASAN: double-free in kasan_remove_zero_shadow+0x9c4/0xa20 Free of addr c0000003c38e0000 by task ndctl/2164 CPU: 34 UID: 0 PID: 2164 Comm: ndctl Not tainted 6.19.0-rc1-00048-gea1013c15392 #157 VOLUNTARY Hardware name: IBM,9080-HEX POWER10 (architected) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_012) hv:phyp pSeries Call Trace: dump_stack_lvl+0x88/0xc4 (unreliable) print_report+0x214/0x63c kasan_report_invalid_free+0xe4/0x110 check_slab_allocation+0x100/0x150 kmem_cache_free+0x128/0x6e0 kasan_remove_zero_shadow+0x9c4/0xa20 memunmap_pages+0x2b8/0x5c0 devm_action_release+0x54/0x70 release_nodes+0xc8/0x1a0 devres_release_all+0xe0/0x140 device_unbind_cleanup+0x30/0x120 device_release_driver_internal+0x3e4/0x450 unbind_store+0xfc/0x110 drv_attr_store+0x78/0xb0 sysfs_kf_write+0x114/0x140 kernfs_fop_write_iter+0x264/0x3f0 vfs_write+0x3bc/0x7d0 ksys_write+0xa4/0x190 system_call_exception+0x190/0x480 system_call_vectored_common+0x15c/0x2ec ---- interrupt: 3000 at 0x7fff93b3d3f4 NIP: 00007fff93b3d3f4 LR: 00007fff93b3d3f4 CTR: 0000000000000000 REGS: c0000003f1b07e80 TRAP: 3000 Not tainted (6.19.0-rc1-00048-gea1013c15392) MSR: 800000000280f033 <SF,VEC,VSX,EE,PR,FP,ME,IR,DR,RI,LE> CR: 48888208 XER: 00000000 <...> NIP [00007fff93b3d3f4] 0x7fff93b3d3f4 LR [00007fff93b3d3f4] 0x7fff93b3d3f4 ---- interrupt: 3000 The buggy address belongs to the object at c0000003c38e0000 which belongs to the cache pgtable-2^9 of size 4096 The buggy address is located 0 bytes inside of 4096-byte region [c0000003c38e0000, c0000003c38e1000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x3c38c head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:c0000003bfd63e01 flags: 0x63ffff800000040(head|node=6|zone=0|lastcpupid=0x7ffff) page_type: f5(slab) raw: 063ffff800000040 c000000140058980 5deadbeef0000122 0000000000000000 raw: 0000000000000000 0000000080200020 00000000f5000000 c0000003bfd63e01 head: 063ffff800000040 c000000140058980 5deadbeef0000122 0000000000000000 head: 0000000000000000 0000000080200020 00000000f5000000 c0000003bfd63e01 head: 063ffff800000002 c00c000000f0e301 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected [ 138.953636] [ T2164] Memory state around the buggy address: [ 138.953643] [ T2164] c0000003c38dff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 138.953652] [ T2164] c0000003c38dff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 138.953661] [ T2164] >c0000003c38e0000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 138.953669] [ T2164] ^ [ 138.953675] [ T2164] c0000003c38e0080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 138.953684] [ T2164] c0000003c38e0100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 138.953692] [ T2164] ================================================================== [ 138.953701] [ T2164] Disabling lock debugging due to kernel taint

Published
Apr 27, 2026
Updated
Nov 11, 2026
EPSS
0.1% · 2th percentile

Report tools

JSON

Action score

31

Monitor

Low priority for now.

CVSS
31 / 40 · 7.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

CISA SSVC decision

Exploitation
none
Automatable
no
Technical impact
partial

Vulnrichment: CISA's decision-tree inputs.

Get told when this record changes

  • Not in KEV: no record of exploitation in the wild
  • No public exploit code on record
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
linuxlinux kernel

Versions reported by the vendor

Affected version ranges reported by the assigning authority (Linux). Independent of NVD's CPE analysis and usually ahead of it.

  • Linux Linux

    • 4.19affected
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before 7d7b2d5c107a1f6302cf0006d859985e7c3ddd1caffected · git
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before 3298bdf5a878ded06351eb293856fa84e050029eaffected · git
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before 2277246ea265cdca64ce6fdea4b26cd6ff0ec4dbaffected · git
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before cec74b2ab7dff866b1d77eaa545b9e8fd14a1f87affected · git
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before a05f77cb227c39c5069aea6f12762a29d1e6c103affected · git
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before f6204f7ff6aff62ce6242a76982c5ba3a9ded707affected · git
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before 85d98614e089a67dc6faa8ca766fe10a639f82b4affected · git
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before b38237a2ea9c6c19836eee2c57037e1f9f103576affected · git
    • 0207df4fa1a869281ddbf72db6203dbf036b3e1a and later · before 51d8c78be0c27ddb91bc2c0263941d8b30a47d3baffected · git
Affected versions · NVD (5)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • linux linux kernel4.19 and later · before 6.6.136
  • linux linux kernel6.7 and later · before 6.12.83
  • linux linux kernel6.13 and later · before 6.18.24
  • linux linux kernel6.19 and later · before 6.19.14
  • linux linux kernel7.0 and later · before 7.0.1

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
Debian:12linuxbefore 6.1.176-16.1.176-1
Debian:13linuxbefore 6.12.85-16.12.85-1
Debian:14linuxbefore 6.19.14-16.19.14-1

Same product

linux: all records

Other highest-scoring records for the same primary product.

  • CVE-2026-31431crypto: algif_aead - Revert to operating out-of-placeKEV
    90Now
  • CVE-2022-0847A flaw was found in the way the "flags" member of the new pipe buffer structure was lacking proper initialization in copy_page_to_iter_pipe…KEV
    89Now
  • CVE-2021-22555Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACEKEV
    85Now

Published before and after this one in the same product

  • ← EarlierCVE-2026-31684Apr 25, 2026 · net: sched: act_csum: validate nested VLAN headers
    22Monitor
  • ← EarlierCVE-2026-31685Apr 25, 2026 · netfilter: ip6t_eui64: reject invalid MAC header for all packets
    37Monitor
  • Later →CVE-2026-31687Apr 27, 2026 · gpio: omap: do not register driver in probe()
    22Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Linux Linux2277246ea265cdca64ce6fdea4b26cd6ff0ec4dbVendor (CNA)
Linux Linux3298bdf5a878ded06351eb293856fa84e050029eVendor (CNA)
Linux Linux51d8c78be0c27ddb91bc2c0263941d8b30a47d3bVendor (CNA)
Linux Linux7d7b2d5c107a1f6302cf0006d859985e7c3ddd1cVendor (CNA)
Linux Linux85d98614e089a67dc6faa8ca766fe10a639f82b4Vendor (CNA)
Linux Linuxa05f77cb227c39c5069aea6f12762a29d1e6c103Vendor (CNA)
Linux Linuxb38237a2ea9c6c19836eee2c57037e1f9f103576Vendor (CNA)
Linux Linuxcec74b2ab7dff866b1d77eaa545b9e8fd14a1f87Vendor (CNA)
Linux Linuxf6204f7ff6aff62ce6242a76982c5ba3a9ded707Vendor (CNA)
debian:linux6.1.176-1 · Debian:12Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2026-316083 days apartsmb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()
    39Monitor
  • CVE-2026-316093 days apartsmb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()
    39Monitor
  • CVE-2026-430114 days apartnet/x25: Fix potential double free of skb
    39Monitor
  • CVE-2026-4341411 days apartscsi: qla2xxx: Completely fix fcport double free
    39Monitor
  • CVE-2026-5299358 days aparttipc: fix double-free in tipc_buf_append()
    39Monitor
  • CVE-2026-6388883 days apartscsi: target: iscsi: Fix CRC overread and double-free in iscsit_handle_text_cmd()
    39Monitor

Not on record for this CVE: EPSS history · patch commit or PR link · researcher credit · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • A low-privileged account is enough.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Local
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-415 · Double Free

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (8 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records