KVM: arm64: Prevent access to vCPU events before init
Noroxi assessment
Priority: Monitor (action score 0/100)
- 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: 0.22% (FIRST EPSS).
- Fixed version: Linux Linux 0aa1b76fe1429629215a7c79820e4b96233ac4a3, 64a04e6320fc5affbadc59dc7024d79f909bfe84, 7b854e68365a84dfa984ee81268e10b9311ac9d2; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1.
Low priority for now. Upgrade to Linux Linux 0aa1b76fe1429629215a7c79820e4b96233ac4a3, 64a04e6320fc5affbadc59dc7024d79f909bfe84, 7b854e68365a84dfa984ee81268e10b9311ac9d2; azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 6.6.157.1-1 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: KVM: arm64: Prevent access to vCPU events before init Another day, another syzkaller bug. KVM erroneously allows userspace to pend vCPU events for a vCPU that hasn't been initialized yet, leading to KVM interpreting a bunch of uninitialized garbage for routing / injecting the exception. In one case the injection code and the hyp disagree on whether the vCPU has a 32bit EL1 and put the vCPU into an illegal mode for AArch64, tripping the BUG() in exception_target_el() during the next injection: kernel BUG at arch/arm64/kvm/inject_fault.c:40! Internal error: Oops - BUG: 00000000f2000800 [#1] SMP CPU: 3 UID: 0 PID: 318 Comm: repro Not tainted 6.17.0-rc4-00104-g10fd0285305d #6 PREEMPT Hardware name: linux,dummy-virt (DT) pstate: 21402009 (nzCv daif +PAN -UAO -TCO +DIT -SSBS BTYPE=--) pc : exception_target_el+0x88/0x8c lr : pend_serror_exception+0x18/0x13c sp : ffff800082f03a10 x29: ffff800082f03a10 x28: ffff0000cb132280 x27: 0000000000000000 x26: 0000000000000000 x25: ffff0000c2a99c20 x24: 0000000000000000 x23: 0000000000008000 x22: 0000000000000002 x21: 0000000000000004 x20: 0000000000008000 x19: ffff0000c2a99c20 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 00000000200000c0 x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000 x8 : ffff800082f03af8 x7 : 0000000000000000 x6 : 0000000000000000 x5 : ffff800080f621f0 x4 : 0000000000000000 x3 : 0000000000000000 x2 : 000000000040009b x1 : 0000000000000003 x0 : ffff0000c2a99c20 Call trace: exception_target_el+0x88/0x8c (P) kvm_inject_serror_esr+0x40/0x3b4 __kvm_arm_vcpu_set_events+0xf0/0x100 kvm_arch_vcpu_ioctl+0x180/0x9d4 kvm_vcpu_ioctl+0x60c/0x9f4 __arm64_sys_ioctl+0xac/0x104 invoke_syscall+0x48/0x110 el0_svc_common.constprop.0+0x40/0xe0 do_el0_svc+0x1c/0x28 el0_svc+0x34/0xf0 el0t_64_sync_handler+0xa0/0xe4 el0t_64_sync+0x198/0x19c Code: f946bc01 b4fffe61 9101e020 17fffff2 (d4210000) Reject the ioctls outright as no sane VMM would call these before KVM_ARM_VCPU_INIT anyway. Even if it did the exception would've been thrown away by the eventual reset of the vCPU's state.
- Published
- Oct 30, 2025
- Updated
- Oct 19, 2026
- EPSS
- 0.2% · 12th percentile
- CWE
- —
Report tools
Action score
0
Monitor
Low priority for now.
- CVSS
- 0 / 40 · —
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.2%
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.
We use this product, ask for helpAffected 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.
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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
- b7b27facc7b50a5fce0afaa3df56157136ce181a and later · before b0ab34a9e4cd5b88b522cc156e792cefe3085334affected · git
- b7b27facc7b50a5fce0afaa3df56157136ce181a and later · before d64461d38972302f0243498ff409b0d54e14e106affected · git
- b7b27facc7b50a5fce0afaa3df56157136ce181a and later · before b498f0da45a388b40195f7198455c62fe366a372affected · git
- b7b27facc7b50a5fce0afaa3df56157136ce181a and later · before 7b854e68365a84dfa984ee81268e10b9311ac9d2affected · git
- b7b27facc7b50a5fce0afaa3df56157136ce181a and later · before c0fcd72e7eb50205dc20731033b0b1c67ecbe4dcaffected · git
- b7b27facc7b50a5fce0afaa3df56157136ce181a and later · before 64a04e6320fc5affbadc59dc7024d79f909bfe84affected · git
- b7b27facc7b50a5fce0afaa3df56157136ce181a and later · before 0aa1b76fe1429629215a7c79820e4b96233ac4a3affected · git
- before 4.19not affected · semver
- 5.10.269 and later · up to and including 5.10.*not affected · semver
Package-level exposure
OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.
| Ecosystem | Package | Affected range | Fix |
|---|---|---|---|
| Debian:12 | linux | before 6.1.187-1 | 6.1.187-1 |
| Debian:12 | linux-6.12 | before 6.12.111-1~deb12u1 | 6.12.111-1~deb12u1 |
| Debian:13 | linux | before 6.12.111-1 | 6.12.111-1 |
| Debian:14 | linux | before 6.17.6-1 | 6.17.6-1 |
Same product
linux: all recordsOther highest-scoring records for the same primary product.
- CVE-2026-74705udp: fix potential use-after-free in tunnel segmentation40Plan
- CVE-2026-74612veth: fix skb length accounting after XDP frag adjustment40Plan
- CVE-2026-74475vxlan: use neigh_ha_snapshot() in route_shortcircuit()40Plan
Published before and after this one in the same product
- ← EarlierCVE-2025-40100Oct 30, 2025 · btrfs: do not assert we found block group item when creating free space tree0Monitor
- ← EarlierCVE-2025-40101Oct 30, 2025 · btrfs: fix memory leaks when rejecting a non SINGLE data profile without an RST0Monitor
- Later →CVE-2025-40103Oct 30, 2025 · smb: client: Fix refcount leak for cifs_sb_tlink0Monitor
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Linux Linux | 0aa1b76fe1429629215a7c79820e4b96233ac4a3 | Vendor (CNA) |
| Linux Linux | 64a04e6320fc5affbadc59dc7024d79f909bfe84 | Vendor (CNA) |
| Linux Linux | 7b854e68365a84dfa984ee81268e10b9311ac9d2 | Vendor (CNA) |
| Linux Linux | b0ab34a9e4cd5b88b522cc156e792cefe3085334 | Vendor (CNA) |
| Linux Linux | b498f0da45a388b40195f7198455c62fe366a372 | Vendor (CNA) |
| Linux Linux | c0fcd72e7eb50205dc20731033b0b1c67ecbe4dc | Vendor (CNA) |
| Linux Linux | d64461d38972302f0243498ff409b0d54e14e106 | Vendor (CNA) |
| azl3 kernel 6.6.152.1-1 on Azure Linux 3.0 | 6.6.157.1-1 · Release Notes | Microsoft (MSRC) |
| debian:linux | 6.1.187-1 · Debian:12 | Package registry (OSV) |
| debian:linux-6.12 | 6.12.111-1~deb12u1 · Debian:12 | Package 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.
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 researchersFinders, 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
No CVSS vector for this record, so attack conditions can't be derived.
Weakness class (CWE)
—
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
- Fix✗ → ✓
For records you follow, these changes also arrive as notifications. →
References
Show all references (6 more)Show less
- git.kernel.org/stable/c/64a04e6320fc5affbadc59dc7024d79f909bfe84
- git.kernel.org/stable/c/7b854e68365a84dfa984ee81268e10b9311ac9d2
- git.kernel.org/stable/c/b0ab34a9e4cd5b88b522cc156e792cefe3085334
- git.kernel.org/stable/c/b498f0da45a388b40195f7198455c62fe366a372
- git.kernel.org/stable/c/c0fcd72e7eb50205dc20731033b0b1c67ecbe4dc
- git.kernel.org/stable/c/d64461d38972302f0243498ff409b0d54e14e106
Vendor advisories and official records. Exploit/PoC links are deliberately left out.