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CVE Record

CVE-2022-31059: Discourse Calendar Event names susceptible to Cross-site Scripting

Discourse Calendar is a calendar plugin for Discourse, an open-source messaging app. Prior to version 1.0.1, parsing and rendering of Event names can be susceptible to cross-site scripting (XSS) attacks. This vulnerability only affects sites which have modified or disabled Discourse’s default Content Security Policy. This issue is patched in version 1.0.1 of the Discourse Calendar plugin. As a workaround, ensure that the Content Security Policy is enabled, and has not been modified in a way which would make it more vulnerable to XSS attacks.

MediumCVSS 6.5Not KEV-listedUpdated
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Glexia's TakeAutomated analysismoderate

Security readout for executives and security teams

Plain-English summary

A flaw in Discourse Calendar before 1.0.1 could let a highly privileged user place malicious script content in calendar event names. The issue mainly matters when a site has weakened or disabled Discourse’s default Content Security Policy, which normally reduces XSS impact.

Executive priority

Treat this as a targeted medium-risk issue. Patch promptly on public or community-facing Discourse sites, especially where CSP was changed or many privileged users exist. It is not supported as an emergency active-exploitation case by the supplied sources.

Technical view

CVE-2022-31059 is a CWE-79 XSS issue in parsing and rendering Discourse Calendar event names. It affects discourse-calendar versions before 1.0.1. CVSS 3.1 is 6.5 with network access, low attack complexity, high privileges required, no user interaction, and high confidentiality and integrity impact.

Likely exposure

Exposure is limited to Discourse deployments using the discourse-calendar plugin before 1.0.1, especially sites that modified or disabled Discourse’s default CSP. Sites without the plugin, or with current plugin versions and intact CSP, are less likely to be exposed.

Exploitation context

The provided sources do not report active exploitation, and this CVE is not listed as KEV in the bundle. Exploitation requires high privileges according to the CVSS vector, so insider, compromised admin, or over-permissioned account scenarios are the main concern.

Researcher notes

Focus validation on plugin version, CSP posture, and who can create or edit event names. The advisory, PR, and commit identify the affected component and fixed version, but the provided bundle does not include exploit telemetry or broader affected-product evidence.

Mitigation direction

  • Upgrade Discourse Calendar to version 1.0.1 or later.
  • Ensure Discourse’s default Content Security Policy is enabled.
  • Review CSP customizations for unsafe script allowances.
  • Reduce calendar event management privileges where unnecessary.
  • Monitor Discourse advisory sources for updated guidance.

Validation and detection

  • Inventory Discourse instances for the discourse-calendar plugin.
  • Confirm installed plugin version is 1.0.1 or newer.
  • Check response headers for an enabled, restrictive CSP.
  • Review whether CSP differs from Discourse defaults.
  • Review privileged account access to calendar event creation.
Prepared
Confidence
high
Sources
5

Public sources used

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.

Potential ATT&CK relevance

Conservative CVE-to-ATT&CK context

These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.

ATT&CK lookup starting points

Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.

cwe · medium confidence lookup

CWE-79: User-session and phishing behavior lookup

Client-side and session-facing weaknesses should be reviewed alongside initial-access and user-execution behaviors. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.

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cve · low confidence lookup

CVE-2022-31059 mapping review

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Vulnerability profileCVE Program record
Severity
Medium
CVSS
6.5 (3.1)
Known Exploited
No
Published

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

Official CVE source material

CNA and ADP enrichment extracted from CVE v5

These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.

1CVSS vectors
0Timeline events
0ADP providers
4Source links

CVSS vector scores

1 official score

We collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.

ScoreVersionSeverityVectorExploitImpactSource
6.5CVSS 3.1MediumCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N1.25.2Primary CVE score

Vulnerability scoring details

Base CVSS 3.1 score

6.5Medium
CVSS 3.1 vector shape for CVE-2022-31059Attack VectorAttack ComplexityPrivileges RequiredUser InteractionScopeConfidentiality ImpactIntegrity ImpactAvailability Impact

Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:N

Attack Vector
NetworkAdjacentLocalPhysical
Attack Complexity
LowHigh
Privileges Required
NoneLowHigh
User Interaction
NoneRequired
Scope
ChangedUnchanged
Confidentiality Impact
HighLowNone
Integrity Impact
HighLowNone
Availability Impact
HighLowNone

Source materials

Affected products

Products and packages named in the record

VendorProductVersion / packageStatus
discoursediscourse-calendar< 1.0.1Listed
Weakness

CWE details

CWE-79

CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.

CWE-79 · source CWE mapping

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.

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