Answer in brief
CVE-2026-55999 records a High severity (CVSS 8.5) vulnerability in xorg-server / xwayland glamor font atlas Heap Buffer Overflow. The current sources do not mark it as known exploited. The current feed maps X.Org/xorg-server (generic), X.Org/xwayland (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.5. 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.
The current feed maps X.Org/xorg-server (generic), X.Org/xwayland (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| X.Org/xorg-servergeneric | >=0 <21.1.24 | 21.1.24 |
| X.Org/xwaylandgeneric | >=0 <24.1.13 | 24.1.13 |
Published upstream
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 8, 2026
Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks.
Quoted source text, attributed separately from HOL analysis.
Answer in brief
CVE-2026-55999 records a High severity (CVSS 8.5) vulnerability in xorg-server / xwayland glamor font atlas Heap Buffer Overflow. The current sources do not mark it as known exploited. The current feed maps X.Org/xorg-server (generic), X.Org/xwayland (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 8.5. 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.
The current feed maps X.Org/xorg-server (generic), X.Org/xwayland (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| X.Org/xorg-servergeneric | >=0 <21.1.24 | 21.1.24 |
| X.Org/xwaylandgeneric | >=0 <24.1.13 | 24.1.13 |
Published upstream
Jul 8, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 9, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 8, 2026
Local attackers with a X connection able to provide PCX fonts to the X server xorg-server before 21.2.24 and xwayland before 24.1.13 could cause a heap buffer overflow via SetFont due to missing glyph boundary checks.
Quoted source text, attributed separately from HOL analysis.