CVE-2025-51846Known exploitationPublic exploitNetwork attack vector

Service crash via unbounded WebSocket frame processing

Published Apr 30, 2026 · Updated Apr 30, 2026

Denial of service in XWiki CryptPad 2025.3.1 through 2026.2.1 allows remote attackers to crash the service via WebSocket traffic. The WebSocket processing path accepts and processes repeated valid frames or fragments without a cumulative per-connection limit. Unauthenticated network access is sufficient; CPU and memory exhaustion interrupts document and session loading for all users.

CVSS severity8.7
High
EPSS probability0.58%
Next 30 days · Sep 16, 2026
Known exploitationReported
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in XWiki CryptPad 2025.3.1 through 2026.2.1 allows remote attackers to crash the service via WebSocket traffic. The WebSocket processing path accepts and processes repeated valid frames or fragments without a cumulative per-connection limit. Unauthenticated network access is sufficient; CPU and memory exhaustion interrupts document and session loading for all users.

The record

CVE
CVE-2025-51846
Published
Apr 30, 2026
Updated
Apr 30, 2026
Vendor
CryptPad
Product
CryptPad
Classifications
CWE-770, T1499.002
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jan 28, 2026Exploitation reportedCryptPad.fr distributed denial-of-service outage
  2. Apr 30, 2026CVE publishedPublication date reported by the CVE source.
  3. Apr 30, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2025.3.1 <2026.2.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

CryptPad · CryptPadversion=2025.3.1 <2026.2.2

Published CVSS scores

7.5CISACVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7CISACVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationReported
Public exploitPublished

Weakness, pattern, technique

CWE-770Allocation of Resources Without Limits or Throttling
T1499.002Service Exhaustion Flood

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Reported exploitation

Technologies

Your stack

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Your stack

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