October 13, 2026

CVE Watchtower

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CVE-2026-55420NVD

Vulnerability Summary

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, under certain non-default configurations, processing of PDF uploads could be exploited to obtain RCE on the server. This issue is patched in 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
Severity Level
HIGH(7.5)
Published Date
Jul 9, 2026
Last Modified
Jul 14, 2026
Exploitation Status
No confirmed exploitation yet
EPSS Score (30-Day)
0.35%Probability
Root Weakness (CWE)
CWE-78: OS Command Injection ↗
The software constructs all or part of an OS command using externally-influenced input, but does not properly neutralize special elements.
CVSS v3.1 Base Metrics — Score 7.5 (HIGH)
Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

Affected & Patched Versions

Affected Versions
  • Discourse Discourse >= 2026.1.0 and < 2026.1.5
  • Discourse Discourse >= 2026.4.0 and < 2026.4.2
  • Discourse Discourse >= 2026.5.0 and < 2026.5.1
  • Discourse Discourse
Patched Versions
  • Discourse Discourse 2026.1.5
  • Discourse Discourse 2026.4.2
  • Discourse Discourse 2026.5.1
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🚫Ad-Free — Uninterrupted experience.
🎁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.
🚫Ad-Free — Uninterrupted experience.

External References