CVE-2021-41119Public exploitNetwork attack vector

Service interruption via colliding JSON object keys

Published Apr 13, 2022 · Updated Apr 22, 2025

Uncontrolled resource consumption in Wire Server before 2022-03-01 allows remote attackers to interrupt service via crafted JSON objects. Aeson builds each JSON object in an unordered-containers HashMap whose predictable FNV hash and linear collision chains make colliding keys take quadratic parsing time. No privileges or user interaction are required; sending untrusted JSON to an exposed parser can consume CPU long enough to deny legitimate requests.

CVSS severity5.3
Medium
EPSS probability1.36%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uncontrolled resource consumption in Wire Server before 2022-03-01 allows remote attackers to interrupt service via crafted JSON objects. Aeson builds each JSON object in an unordered-containers HashMap whose predictable FNV hash and linear collision chains make colliding keys take quadratic parsing time. No privileges or user interaction are required; sending untrusted JSON to an exposed parser can consume CPU long enough to deny legitimate requests.

The record

CVE
CVE-2021-41119
Published
Apr 13, 2022
Updated
Apr 22, 2025
Vendor
Wire Swiss GmbH
Product
Wire Server
Classifications
CWE-400, T1499.003
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 13, 2022CVE publishedPublication date reported by the CVE source.
  2. Apr 22, 2025Record 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=< v2022-03-01

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Wire Swiss GmbH · Wire Serverversion=< v2022-03-01

Published CVSS scores

5.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

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.

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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 exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-400Uncontrolled Resource Consumption
T1499.003Application Exhaustion Flood

Public exploit references

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

Technologies

Your stack

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Your stack

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