Discourse up to 2026.1.3/2026.3.0/2026.4.0 Calendar Event authorization

CVSS Meta Temp Score
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CTI Interest Score
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5.2$0-$5k1.16

Summaryinfo

A vulnerability, which was classified as problematic, has been found in Discourse up to 2026.1.3/2026.3.0/2026.4.0. This vulnerability affects unknown code of the component Calendar Event Handler. Performing a manipulation results in authorization. This vulnerability is identified as CVE-2026-45085. The attack can be initiated remotely. There is not any exploit available. It is advisable to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic has been found in Discourse up to 2026.1.3/2026.3.0/2026.4.0. This affects an unknown functionality of the component Calendar Event Handler. The manipulation with an unknown input leads to a authorization vulnerability. CWE is classifying the issue as CWE-862. The product does not perform an authorization check when an actor attempts to access a resource or perform an action. This is going to have an impact on confidentiality. The summary by CVE is:

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, four authorization/disclosure issues in the chat plugin (one also involving discourse-calendar): read-only category users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel's current last_message (often unrelated DM content), and calendar event payloads exposed the attached chat channel and its last message to viewers without chat access (including anonymous users). This affects sites with the chat plugin enabled; the calendar issue additionally requires discourse-calendar. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.

It is possible to read the advisory at github.com. This vulnerability is uniquely identified as CVE-2026-45085 since 05/08/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 2026.1.4, 2026.3.1 or 2026.4.1 eliminates this vulnerability.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.3
VulDB Meta Temp Score: 5.2

VulDB Base Score: 5.3
VulDB Temp Score: 5.1
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 5.3
CNA Vector (GitHub_M): 🔒

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Authorization
CWE: CWE-862 / CWE-863 / CWE-285
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Discourse 2026.1.4/2026.3.1/2026.4.1

Timelineinfo

05/08/2026 CVE reserved
06/13/2026 +36 days Advisory disclosed
06/13/2026 +0 days VulDB entry created
06/13/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: GHSA-rw8j-p2gv-q33w
Status: Confirmed

CVE: CVE-2026-45085 (🔒)
GCVE (CVE): GCVE-0-2026-45085
GCVE (VulDB): GCVE-100-370791

Entryinfo

Created: 06/13/2026 07:08
Changes: 06/13/2026 07:08 (64)
Complete: 🔍
Cache ID: 216::103

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Discussion

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