Discourse up to 2026.1.4/2026.4.1/2026.5.0 EventSerializer deserialization

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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3.4$0-$5k0.56

Summaryinfo

A vulnerability classified as problematic was found in Discourse up to 2026.1.4/2026.4.1/2026.5.0. This impacts an unknown function of the component EventSerializer. Such manipulation leads to deserialization. This vulnerability is uniquely identified as CVE-2026-45780. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability was found in Discourse up to 2026.1.4/2026.4.1/2026.5.0. It has been rated as problematic. Affected by this issue is an unknown function of the component EventSerializer. The manipulation with an unknown input leads to a deserialization vulnerability. Using CWE to declare the problem leads to CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. Impacted is confidentiality. CVE summarizes:

Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, EventSerializer could expose invited group names, sample invitees, and attendance statistics to users who could view the topic but were not entitled to view the private event invitee list. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

The advisory is available at github.com. This vulnerability is handled as CVE-2026-45780 since 05/13/2026. The exploitation is known to be easy. The attack may be launched remotely. Successful exploitation requires user interaction by the victim. The technical details are unknown and an exploit is not available.

Upgrading to version 2026.1.5, 2026.4.2 or 2026.5.1 eliminates this vulnerability.

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Productinfo

Type

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 3.5
VulDB Meta Temp Score: 3.4

VulDB Base Score: 3.5
VulDB Temp Score: 3.4
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

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

Exploitinginfo

Class: Deserialization
CWE: CWE-502 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Upgrade: Discourse 2026.1.5/2026.4.2/2026.5.1

Timelineinfo

05/13/2026 CVE reserved
07/09/2026 +57 days VulDB entry created
07/10/2026 +0 days Advisory disclosed
07/10/2026 +0 days VulDB entry last update

Sourcesinfo

Product: github.com

Advisory: github.com
Status: Confirmed

CVE: CVE-2026-45780 (🔒)
GCVE (CVE): GCVE-0-2026-45780
GCVE (VulDB): GCVE-100-377342

Entryinfo

Created: 07/10/2026 00:38
Changes: 07/10/2026 00:38 (53)
Complete: 🔍
Cache ID: 216::103

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Discussion

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