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TI-2026-45505 Aliases CVE-2026-63940GHSA-jx39-q92m-wf39

KVM: SEV: Ignore Port I/O requests of length '0'

Priority MEDIUM 41CWE-190Published · Updated

Key facts

Attack vector
Local
Privileges required
None
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 3 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-190 and the CVSS impact.

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Ignore Port I/O requests of length '0' Explicitly ignore Port I/O requests of length '0' (or count '0'), so that setting up the software scratch area (and other code) doesn't have to worry about underflowing the length, and to allow for WARNing on trying to configure the scratch area with len==0.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00186 8th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.1.191, 6.6.160, 6.12.95 +3Red Hat: 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

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

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.11 and later6.1.191, 6.6.160, 6.12.95, 6.18.35, 7.0.12, 7.1Patch availableCNA
  • Linux VendorLinux Affected 5.11 and later Fixed in 6.1.191, 6.6.160, 6.12.95, 6.18.35, 7.0.12, 7.1 Patch available CNA

CPE configurations NVD · 6

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*5.11 to before 6.6.160; 6.7 to before 6.12.95; 6.13 to before 6.18.35; 6.19 to before 7.0.12VulnerableLinux
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:7.1:rc3:*:*:*:*:*:*7.1 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:*7.1 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:*7.1 rc5VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.11 to before 6.6.160; 6.7 to before 6.12.95; 6.13 to before 6.18.35; 6.19 to before 7.0.12 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
  • cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* Versions 7.1 rc5 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.1.191, 6.6.160, 6.12.95, 6.18.35, 7.0.12, 7.1

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 10AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet
Red Hat Enterprise Linux 9AffectedNo fix yet
Not affected: 2 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-63940
  2. 2026-10-03 Alias added: GHSA-jx39-q92m-wf39
  3. 2026-10-16 CISA SSVC decision points changed
  4. 2026-10-16 Priority changed: LOW → MEDIUM
  5. 2026-10-19 Weakness changed · CISA ADP
  6. 2026-10-21 Fix available: Linux/[email protected], Linux/Linux@bbd3a27e4f99fdcad82d12d79c04a95dff1ff70b · CNA
  7. 2026-10-21 1 new reference · CNA
  8. 2026-10-28 Weakness changed · NVD
  9. 2026-10-30 Fix available: Linux/[email protected], Linux/Linux@c8aa0a79ab0b23cde4c46ccff78e63be35733e04 · CNA
  10. 2026-10-30 1 new reference · CNA

References

Patch 5

Other 1

  • 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