BIT-discourse-2026-91159

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Import Source
https://github.com/bitnami/vulndb/tree/main/data/discourse/BIT-discourse-2026-91159.json
JSON Data
https://api.osv.dev/v1/vulns/BIT-discourse-2026-91159
Aliases
Published
2026-10-21T08:47:55Z
Modified
2026-10-21T12:11:22Z
Summary
Discourse: Stored oEmbed HTML injection via allowed iframe
Details

Discourse is an open-source discussion platform. Prior to 2026.9.0, 2026.8.1, 2026.7.3, and 2026.1.9, oEmbed processing treated an entire attacker-controlled HTML fragment as trusted when the fragment contained an iframe whose source matched the configured allowlist. A user with posting permission who controlled a public webpage and its oEmbed response could combine an allowlisted iframe with unrelated sibling HTML or CSS, causing stored visual overlays or other styled content to appear in post content and enabling misleading or fraudulent user interfaces. Exploitation requires a posting account, control of the fetched webpage and oEmbed response, and an allowlisted iframe source. The issue affects content integrity but does not expose restricted data, disrupt availability, or require interaction with Discourse Content Security Policy. This issue is fixed in versions 2026.9.0, 2026.8.1, 2026.7.3, and 2026.1.9.

Database specific 
{
    "cpes":  [
        "cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*",
        "cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:*"
    ],
    "severity":  "High"
}
References

Affected packages

Bitnami / discourse

Package

Name
discourse
Purl
pkg:bitnami/discourse

Severity

  • 7.7 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:H/A:N CVSS Calculator

Affected ranges

Type
SEMVER
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2026.1.9
Introduced
2026.7.0
Fixed
2026.7.3
Introduced
2026.8.0
Fixed
2026.8.1
Introduced
2026.8.99
Fixed
2026.9.0

Database specific

source 
"https://github.com/bitnami/vulndb/tree/main/data/discourse/BIT-discourse-2026-91159.json"