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NVD / CVE Program· CNA Linux

CVE-2026-23345: arm64: gcs: Do not set PTE_SHARED on GCS mappings if FEAT_LPA2 is enabled

Noroxi assessment

Priority: Monitor (action score 22/100)

  • 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 1df3ef7e612d6ccbae5a48e1121553c47c2123d6, 8a85b3131225a8c8143ba2ae29c0eef8c1f9117f, ca1684dd297bf0725c1d487cff80e615497accf6.

Low priority for now. Upgrade to Linux Linux 1df3ef7e612d6ccbae5a48e1121553c47c2123d6, 8a85b3131225a8c8143ba2ae29c0eef8c1f9117f, ca1684dd297bf0725c1d487cff80e615497accf6 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: arm64: gcs: Do not set PTE_SHARED on GCS mappings if FEAT_LPA2 is enabled When FEAT_LPA2 is enabled, bits 8-9 of the PTE replace the shareability attribute with bits 50-51 of the output address. The _PAGE_GCS{,_RO} definitions include the PTE_SHARED bits as 0b11 (this matches the other _PAGE_* definitions) but using this macro directly leads to the following panic when enabling GCS on a system/model with LPA2: Unable to handle kernel paging request at virtual address fffff1ffc32d8008 Mem abort info: ESR = 0x0000000096000004 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x04: level 0 translation fault Data abort info: ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 swapper pgtable: 4k pages, 52-bit VAs, pgdp=0000000060f4d000 [fffff1ffc32d8008] pgd=100000006184b003, p4d=0000000000000000 Internal error: Oops: 0000000096000004 [#1] SMP CPU: 0 UID: 0 PID: 513 Comm: gcs_write_fault Tainted: G M 7.0.0-rc1 #1 PREEMPT Tainted: [M]=MACHINE_CHECK Hardware name: QEMU QEMU Virtual Machine, BIOS 2025.02-8+deb13u1 11/08/2025 pstate: 03402005 (nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : zap_huge_pmd+0x168/0x468 lr : zap_huge_pmd+0x2c/0x468 sp : ffff800080beb660 x29: ffff800080beb660 x28: fff00000c2058180 x27: ffff800080beb898 x26: fff00000c2058180 x25: ffff800080beb820 x24: 00c800010b600f41 x23: ffffc1ffc30af1a8 x22: fff00000c2058180 x21: 0000ffff8dc00000 x20: fff00000c2bc6370 x19: ffff800080beb898 x18: ffff800080bebb60 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000007 x14: 000000000000000a x13: 0000aaaacbbbffff x12: 0000000000000000 x11: 0000ffff8ddfffff x10: 00000000000001fe x9 : 0000ffff8ddfffff x8 : 0000ffff8de00000 x7 : 0000ffff8da00000 x6 : fff00000c2bc6370 x5 : 0000ffff8da00000 x4 : 000000010b600000 x3 : ffffc1ffc0000000 x2 : fff00000c2058180 x1 : fffff1ffc32d8000 x0 : 000000c00010b600 Call trace: zap_huge_pmd+0x168/0x468 (P) unmap_page_range+0xd70/0x1560 unmap_single_vma+0x48/0x80 unmap_vmas+0x90/0x180 unmap_region+0x88/0xe4 vms_complete_munmap_vmas+0xf8/0x1e0 do_vmi_align_munmap+0x158/0x180 do_vmi_munmap+0xac/0x160 __vm_munmap+0xb0/0x138 vm_munmap+0x14/0x20 gcs_free+0x70/0x80 mm_release+0x1c/0xc8 exit_mm_release+0x28/0x38 do_exit+0x190/0x8ec do_group_exit+0x34/0x90 get_signal+0x794/0x858 arch_do_signal_or_restart+0x11c/0x3e0 exit_to_user_mode_loop+0x10c/0x17c el0_da+0x8c/0x9c el0t_64_sync_handler+0xd0/0xf0 el0t_64_sync+0x198/0x19c Code: aa1603e2 d34cfc00 cb813001 8b011861 (f9400420) Similarly to how the kernel handles protection_map[], use a gcs_page_prot variable to store the protection bits and clear PTE_SHARED if LPA2 is enabled. Also remove the unused PAGE_GCS{,_RO} macros.

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Mar 25, 2026
Updated
Jun 17, 2026
EPSS
0.1% · 2th percentile
CWE
—

Report tools

JSON

Action score

22

Monitor

Low priority for now.

CVSS
22 / 40 · 5.5 / 10
CISA KEV
0 / 30 · Not listed
EPSS
0 / 30 · 0.1%

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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

Affected versions

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

  • linux linux kernel6.13.1 and later · before 6.18.17
  • linux linux kernel6.19 and later · before 6.19.7
  • linux linux kernel6.13
  • linux linux kernel7.0

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

    • 6.13affected
    • 6497b66ba6945f142902c7e8fce86e47016ead1c and later · before ca1684dd297bf0725c1d487cff80e615497accf6affected · git
    • 6497b66ba6945f142902c7e8fce86e47016ead1c and later · before 1df3ef7e612d6ccbae5a48e1121553c47c2123d6affected · git
    • 6497b66ba6945f142902c7e8fce86e47016ead1c and later · before 8a85b3131225a8c8143ba2ae29c0eef8c1f9117faffected · git
    • before 6.13not affected · semver
    • 6.18.17 and later · up to and including 6.18.*not affected · semver
    • 6.19.7 and later · up to and including 6.19.*not affected · semver
    • 7.0 and laternot affected · original_commit_for_fix

Package-level exposure

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

EcosystemPackageAffected rangeFix
Debian:14linuxbefore 6.19.8-16.19.8-1

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-2026-23342Mar 25, 2026 · bpf: Fix race in cpumap on PREEMPT_RT
    18Monitor
  • ← EarlierCVE-2026-23344Mar 25, 2026 · crypto: ccp - Fix use-after-free on error path
    31Monitor
  • Later →CVE-2026-23346Mar 25, 2026 · arm64: io: Extract user memory type in ioremap_prot()
    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 Linux1df3ef7e612d6ccbae5a48e1121553c47c2123d6Vendor (CNA)
Linux Linux8a85b3131225a8c8143ba2ae29c0eef8c1f9117fVendor (CNA)
Linux Linuxca1684dd297bf0725c1d487cff80e615497accf6Vendor (CNA)
debian:linux6.19.8-1 · Debian:14Package 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.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

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

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

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

Weakness class (CWE)

—

CVSS vector

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

Change log

  1. Fix✗ → ✓

For records you follow, these changes also arrive as notifications. →

References

Show all references (2 more)

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

All records