Discourse up to 2026.1.4/2026.4.1/2026.5.0 PostRevisionSerializer 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-$5k0.00

Summaryinfo

A vulnerability classified as problematic was found in Discourse up to 2026.1.4/2026.4.1/2026.5.0. Affected by this issue is some unknown functionality of the component PostRevisionSerializer. Executing a manipulation can lead to deserialization. This vulnerability is handled as CVE-2026-59828. The attack can be executed remotely. There is not any exploit available.

Detailsinfo

A vulnerability has been found in Discourse up to 2026.1.4/2026.4.1/2026.5.0 and classified as problematic. This vulnerability affects an unknown function of the component PostRevisionSerializer. The manipulation with an unknown input leads to a deserialization vulnerability. The CWE definition for the vulnerability is CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. As an impact it is known to affect 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, post revisions that should be hidden from regular users could be leaked through visible diffs on adjacent revisions serialized by PostRevisionSerializer. This issue is fixed in versions 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.

The advisory is shared for download at github.com. This vulnerability was named CVE-2026-59828 since 07/07/2026. The exploitation appears to be easy. The attack can be initiated remotely. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available.

Upgrading to version 2026.6.0, 2026.5.1, 2026.4.2 or 2026.1.5 eliminates this vulnerability.

Once again VulDB remains the best 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: 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 2026.6.0/2026.5.1/2026.4.2/2026.1.5

Timelineinfo

07/07/2026 CVE reserved
07/09/2026 +2 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-2026-59828 (🔒)
GCVE (CVE): GCVE-0-2026-59828
GCVE (VulDB): GCVE-100-377356

Entryinfo

Created: 07/10/2026 01:10
Changes: 07/10/2026 01:10 (53)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

Discussion

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