CVE-2026-27454

Source
https://cve.org/CVERecord?id=CVE-2026-27454
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27454.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2026-27454
Aliases
Published
2026-03-19T20:39:28Z
Modified
2026-08-12T03:51:42Z
Severity
  • 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N CVSS Calculator
Summary
Discourse has check revision visibility on posts endpoint
Details

Discourse is an open-source discussion platform. Prior to versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, requesting /posts/:id.json?version=X bypassed authorization checks on post revisions. The display_post method called post.revert_to directly without verifying whether the revision was hidden or if the user had permission to view edit history. This meant hidden revisions (intentionally concealed by staff) could be read by any user by simply enumerating version numbers. Starting in versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2, Discourse looks up the PostRevision and call guardian.ensure_can_see! before reverting, consistent with how the /posts/:id/revisions/:revision endpoint already authorizes access. No known workarounds are available.

Database specific
{
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
        "CWE-862"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/27xxx/CVE-2026-27454.json"
}
References

Affected packages

Git / github.com/discourse/discourse

Affected ranges

Type
GIT
Repo
https://github.com/discourse/discourse
Events
Database specific
Show details
{
    "cpe": [
        "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
        "cpe:2.3:a:discourse:discourse:2026.3.0:*:*:*:latest:*:*:*"
    ],
    "extracted_events": [
        {
            "introduced": "2026.1.0"
        },
        {
            "fixed": "2026.1.2"
        },
        {
            "introduced": "2026.2.0"
        },
        {
            "fixed": "2026.2.1"
        },
        {
            "introduced": "2026.3.0"
        },
        {
            "last_affected": "2026.3.0"
        }
    ],
    "source": [
        "CPE_RANGE",
        "CPE_STRING",
        "REFERENCES"
    ]
}

Affected versions

2026.*
2026.3.0
= 2026.*
= 2026.3.0-latest
Other
esr
stable
v2026.*
v2026.1.0
v2026.1.0-latest
v2026.1.1
v2026.2.0
v2026.2.0-latest
v2026.3.0-latest

Database specific

source
"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-27454.json"