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Heap overflow in spice-server GLZ dictionary restore path

Priority LOW 35CWE-190Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
High
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
No fix listed

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

Summary

Red Hat Enterprise Linux 6, 7 and 8 ship spice-server, which is affected. The GLZ encoder dictionary restore path truncates a size_t allocation size to int (CWE-190) when calling the malloc callback, causing a heap buffer overflow. A malicious authenticated SPICE client can trigger it during VM live migration by sending a crafted max_encoders value in migration data.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Description from the CNA

A flaw was found in spice-server. The GLZ encoder dictionary restore path truncates a size_t allocation size to int when calling the malloc callback, allowing a malicious authenticated SPICE client during VM live migration to trigger a massive heap buffer overflow by sending a crafted max_encoders value in migration data.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.0048 41st percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

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
Red HatRed Hat Enterprise Linux 6——No fix listedCNA
Red HatRed Hat Enterprise Linux 7——No fix listedCNA
Red HatRed Hat Enterprise Linux 8——No fix listedCNA
  • Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
  • Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA

CPE names CNA · 3

CPEVersionsRoleVendor
cpe:/o:redhat:rhel_els:66—Red Hat
cpe:/o:redhat:rhel_els:77—Red Hat
cpe:/a:redhat:enterprise_linux:88—Red Hat
  • cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
  • cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
  • cpe:/a:redhat:enterprise_linux:8 Versions 8 — ·Red Hat

Remediation

The sources list no fixed version for Red Hat Enterprise Linux 6, 7 or 8, and no planned fix for these products.

Written with Claude Haiku 5.5 from the sources below · 2026-10-28

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix yet
Red Hat Enterprise Linux 7AffectedNo fix yet
Red Hat Enterprise Linux 8AffectedNo fix yet

Timeline

  1. 2026-10-16 Threatist record created from CVE-2026-105959
  2. 2026-10-16 Affected versions changed · Red Hat
  3. 2026-10-16 CVSS score added · Red Hat
  4. 2026-10-16 Alias added: GHSA-m5f2-676c-jfj7

References

  • TI-2019-15875 Protection mechanism failure in Jenkins Pipeline: Groovy Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-15874 Protection mechanism failure in Jenkins Script Security Plugin KEVCVSS 3.1CRITICAL 9.9
  • TI-2019-08259 Underflow in PHP-FPM can lead to RCE KEVCVSS 3.1CRITICAL 9.8
  • TI-2019-05363 Code injection in Elastic Kibana KEVCVSS 3.1CRITICAL 10.0
  • TI-2019-03949 Out-of-bounds write in ESXi and Horizon DaaS KEVCVSS 3.1CRITICAL 9.8
  • TI-2018-16080 A code execution vulnerability exists in the Stapler web framework used by Jenkins 2.153… KEVCVSS 3.1CRITICAL 9.8
See all 7413 →

Sources