CVE-2025-48053

Discourse vulnerable to DoS via large URL payload in PM to a bot

HIGH
7.5
CVSS Score
Published: June 9, 2025 at 12:30 PM UTC
Updated: June 17, 2026 at 09:29 AM UTC
1 product affected across 1 vendorDiscourse

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Severity
HIGH7.5
Exploit prediction
EPSS 0.4%
SSVC
No known exploit

Description

Discourse is an open-source discussion platform. Prior to version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch, sending a malicious URL in a PM to a bot user can cause a reduced the availability of a Discourse instance. This issue is patched in version 3.4.4 of the `stable` branch, version 3.5.0.beta5 of the `beta` branch, and version 3.5.0.beta6-dev of the `tests-passed` branch. No known workarounds are available.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 3.4.4v < 3.5.0v < 3.5.0.beta5v < 3.5.0.beta6-dev3.5.0 beta13.5.0 beta23.5.0 beta33.5.0 beta4
Affected range stops below 3.4.4, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.5.0, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.5.0.beta5, so it looks safe — our inference, not a vendor statement
Affected range stops below 3.5.0.beta6-dev, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

SSVC — Action Prioritization

SSVCNo known exploitAutomatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
NETWORK
Complexity
LOW
Privileges
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
CWE-400CWE-770

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