October 30, 2026

CVE Watchtower

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CVE-2026-55999NVD

Vulnerability Summary

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.
Severity Level
HIGH(8.5)
Published Date
Jul 8, 2026
Last Modified
Jul 9, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.27%Probability
Root Weakness (CWE)
CWE-122: Unknown/Unlisted Weakness ↗
Refer to the official MITRE database for detailed architectural specifications regarding this weakness.
CVSS v3.1 Base Metrics — Score 8.5 (HIGH)
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredLow
User InteractionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

Affected & Patched Versions

Affected Versions
  • X.org X Server < 21.2.24
  • X.org Xwayland < 24.1.13
Patched Versions
  • X.org X Server 21.2.24
  • X.org Xwayland 24.1.13
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🎁7-Day Free Trial — Try Pro or Team, no card required.
📧Email Delivery — Threat intel straight to your inbox.
♾️Unlimited Vendors — Track your entire stack.
🚨All New CVEs — Be the first to know.
📈EPSS Spike Alerts — Catch rising risk before it peaks.
🎯Custom EPSS/CVSS — Filter noise, focus on risk.
🛡️Exploit Intel — A 2nd confirmed-exploit signal beyond KEV.
🐙GitHub Issues — Auto-tracked, no duplicates.
📬Weekly Digest — One clean summary, not inbox spam.
🏷️Watchlist Groups — Tag alerts by team (Infra/AppSec/SOC).
💬Webhooks — Slack & Teams integration.
🔀Smart Routing — Critical alerts to one channel, rest to another.
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External References