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NVD / CVE Program· CNA Linux

CVE-2025-39704: LoongArch: KVM: Fix stack protector issue in send_ipi_data()

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: 0.15% (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 5c68549c81bcca70fc464e305ffeefd9af968287, b5b49d341f90eed6de794b6ff34ad3dd66d34343.
  • Severity is disputed: the assigning authority (CNA) scores it 8.8, NVD 5.5.

Low priority for now. Upgrade to Linux Linux 5c68549c81bcca70fc464e305ffeefd9af968287, b5b49d341f90eed6de794b6ff34ad3dd66d34343 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: LoongArch: KVM: Fix stack protector issue in send_ipi_data() Function kvm_io_bus_read() is called in function send_ipi_data(), buffer size of parameter *val should be at least 8 bytes. Since some emulation functions like loongarch_ipi_readl() and kvm_eiointc_read() will write the buffer *val with 8 bytes signed extension regardless parameter len. Otherwise there will be buffer overflow issue when CONFIG_STACKPROTECTOR is enabled. The bug report is shown as follows: Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: send_ipi_data+0x194/0x1a0 [kvm] CPU: 11 UID: 107 PID: 2692 Comm: CPU 0/KVM Not tainted 6.17.0-rc1+ #102 PREEMPT(full) Stack : 9000000005901568 0000000000000000 9000000003af371c 900000013c68c000 900000013c68f850 900000013c68f858 0000000000000000 900000013c68f998 900000013c68f990 900000013c68f990 900000013c68f6c0 fffffffffffdb058 fffffffffffdb0e0 900000013c68f858 911e1d4d39cf0ec2 9000000105657a00 0000000000000001 fffffffffffffffe 0000000000000578 282049464555206e 6f73676e6f6f4c20 0000000000000001 00000000086b4000 0000000000000000 0000000000000000 0000000000000000 9000000005709968 90000000058f9000 900000013c68fa68 900000013c68fab4 90000000029279f0 900000010153f940 900000010001f360 0000000000000000 9000000003af3734 000000004390000c 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d ... Call Trace: [<9000000003af3734>] show_stack+0x5c/0x180 [<9000000003aed168>] dump_stack_lvl+0x6c/0x9c [<9000000003ad0ab0>] vpanic+0x108/0x2c4 [<9000000003ad0ca8>] panic+0x3c/0x40 [<9000000004eb0a1c>] __stack_chk_fail+0x14/0x18 [<ffff8000023473f8>] send_ipi_data+0x190/0x1a0 [kvm] [<ffff8000023313e4>] __kvm_io_bus_write+0xa4/0xe8 [kvm] [<ffff80000233147c>] kvm_io_bus_write+0x54/0x90 [kvm] [<ffff80000233f9f8>] kvm_emu_iocsr+0x180/0x310 [kvm] [<ffff80000233fe08>] kvm_handle_gspr+0x280/0x478 [kvm] [<ffff8000023443e8>] kvm_handle_exit+0xc0/0x130 [kvm]

MediumCVSS 5.5 · v3.1—No exploit Fix available
Published
Sep 5, 2025
Updated
Oct 19, 2026
EPSS
0.1% · 4th percentile

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%

CNA vs NVD score

NVD
5.5
CNA · Linux
8.8
3.3 point gap

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

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

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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When you'll hear from us

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  • when exploit code appears or is weaponized
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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 and later · before 6.16.4
  • linux linux kernel6.17

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
    • daee2f9cae5510ba1bd9eed6b0cf0ca8dc276118 and later · before b5b49d341f90eed6de794b6ff34ad3dd66d34343affected · git
    • daee2f9cae5510ba1bd9eed6b0cf0ca8dc276118 and later · before 5c68549c81bcca70fc464e305ffeefd9af968287affected · git
    • before 6.13not affected · semver
    • 6.16.4 and later · up to and including 6.16.*not affected · semver
    • 6.17 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 6.16.5-16.16.5-1

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-2025-39702Sep 5, 2025 · ipv6: sr: Fix MAC comparison to be constant-time
    28Monitor
  • ← EarlierCVE-2025-39703Sep 5, 2025 · net, hsr: reject HSR frame if skb can't hold tag
    22Monitor
  • Later →CVE-2025-39705Sep 5, 2025 · drm/amd/display: fix a Null pointer dereference vulnerability
    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 Linux5c68549c81bcca70fc464e305ffeefd9af968287Vendor (CNA)
Linux Linuxb5b49d341f90eed6de794b6ff34ad3dd66d34343Vendor (CNA)
debian:linux6.16.5-1 · 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.

No history yet (it accumulates with the daily EPSS job).

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.

  • CVE-2026-43185243 days apartksmbd: fix signededness bug in smb_direct_prepare_negotiation()
    39Monitor
  • CVE-2025-3845942 days apartatm: clip: Fix infinite recursive call of clip_push().
    31Monitor
  • CVE-2026-53202293 days apartaccel/ivpu: Fix signed integer truncation in IPC receive
    31Monitor
  • CVE-2026-53267293 days apartnetfilter: nft_ct: bail out on template ct in get eval
    31Monitor
  • CVE-2024-35886474 days apartipv6: Fix infinite recursion in fib6_dump_done().
    31Monitor
  • CVE-2026-53395317 days apartnfsd: fix dead ACL conflict guard in nfsd4_create
    30Monitor

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)

CWE-674 · Uncontrolled Recursion

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.

ATT&CK techniques

—

Change log

  1. Fix✗ → ✓

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

References

Show all references (1 more)

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

All records