High · CVSS 7.5CVE-2026-105959

Spice-server: spice: heap buffer overflow via glz dictionary max_encoders integer truncationCVE-2026-105959

Answer in brief

CVE-2026-105959 records a High severity (CVSS 7.5) vulnerability in Spice-server: spice: heap buffer overflow via glz dictionary max_encoders integer truncation. The current sources do not mark it as known exploited. The current feed maps Red Hat/spice (generic), Red Hat/spice-server (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Oct 16, 2026Updated Oct 16, 2026Source checked Oct 16, 2026First seen by HOL Oct 16, 2026Material review Oct 16, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Not reported

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Red Hat/spice (generic), Red Hat/spice-server (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Red Hat/spicegeneric	*	Not reported
Red Hat/spice-servergeneric	*	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Red Hat/spice, Red Hat/spice-server.
Review the reported fix. Source-reported workaround: This vulnerability is only exploitable during VM live migration by an authenticated SPICE client. If live migration is not required, disabling it eliminates the attack surface. If live migration is needed, restrict SPICE client connections to trusted networks using firewall rules and enforce strong authentication (TLS with mutual certificate validation, or SASL with strong credentials) to limit who can connect as a SPICE client.

Evidence timeline and material changes

Published upstream
Oct 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Oct 16, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Oct 16, 2026

Sources and claim methodology

Upstream source description

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.

Quoted source text, attributed separately from HOL analysis.