CVE-2021-43793Network attack vector

Poll result manipulation via missing vote-count validation

Published Dec 1, 2021 · Updated Aug 4, 2024

Poll voting-limit bypass in Discourse allows remote authenticated users to cast multiple choices in single-option polls. DiscoursePoll::Poll.vote filtered submitted option digests for validity but did not compare the resulting count with the poll's single-choice limit before recording votes. A forum account and access to an open poll are required; exploitation changes poll vote records and results but does not disclose data or interrupt service.

CVSS severity4.3
Medium
EPSS probability0.76%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Poll voting-limit bypass in Discourse allows remote authenticated users to cast multiple choices in single-option polls. DiscoursePoll::Poll.vote filtered submitted option digests for validity but did not compare the resulting count with the poll's single-choice limit before recording votes. A forum account and access to an open poll are required; exploitation changes poll vote records and results but does not disclose data or interrupt service.

The record

CVE
CVE-2021-43793
Published
Dec 1, 2021
Updated
Aug 4, 2024
Vendor
Discourse
Product
Discourse
Classifications
CWE-269, T1565.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 1, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record 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=stable < 2.7.11
  2. Affected versionversion=tests-passed < 2.8.0.beta9

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Discourse · Discourseversion=stable < 2.7.11; version=tests-passed < 2.8.0.beta9

Published CVSS scores

4.0NIST NVDAV:N/AC:L/Au:S/C:N/I:P/A:N
4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A: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.

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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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-269Improper Privilege Management
T1565.001Stored Data Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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