Vulnerability from bitnami_vulndb
Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the video placeholder component allowed crafted HTML to cause an attribute breakout and inject an attacker-controlled event handler. An authenticated user with default trust-level posting privileges could store the crafted placeholder in a post. When another user opened the post and clicked the video play overlay, the handler could execute arbitrary JavaScript in the viewer's session. Default Content Security Policy settings block inline event handlers, but instances with CSP disabled or relaxed could allow the script to read page content and make authenticated requests as the viewer. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.
{
"affected": [
{
"package": {
"ecosystem": "Bitnami",
"name": "discourse",
"purl": "pkg:bitnami/discourse"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "2026.8.0"
}
],
"type": "SEMVER"
}
],
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N",
"type": "CVSS_V3"
}
]
}
],
"aliases": [
"CVE-2026-91122"
],
"database_specific": {
"cpes": [
"cpe:2.3:a:discourse:discourse:*:*:*:*:stable:*:*:*",
"cpe:2.3:a:discourse:discourse:*:*:*:*:beta:*:*:*"
],
"severity": "High"
},
"details": "Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the video placeholder component allowed crafted HTML to cause an attribute breakout and inject an attacker-controlled event handler. An authenticated user with default trust-level posting privileges could store the crafted placeholder in a post. When another user opened the post and clicked the video play overlay, the handler could execute arbitrary JavaScript in the viewer\u0027s session. Default Content Security Policy settings block inline event handlers, but instances with CSP disabled or relaxed could allow the script to read page content and make authenticated requests as the viewer. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.",
"id": "BIT-discourse-2026-91122",
"modified": "2026-10-01T09:55:18.588Z",
"published": "2026-10-01T09:29:29.486Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/discourse/discourse/commit/05d92b8749f68d2626cbe65ec7adde7562a0283d"
},
{
"type": "WEB",
"url": "https://github.com/discourse/discourse/commit/5674b3e6594825c28d2678e55057fd6802f11031"
},
{
"type": "WEB",
"url": "https://github.com/discourse/discourse/commit/c3993e318e172389be5c98455177876f1dd87dda"
},
{
"type": "WEB",
"url": "https://github.com/discourse/discourse/commit/d7126af3264b672d2201d84c18a37cb8627424a8"
},
{
"type": "WEB",
"url": "https://github.com/discourse/discourse/pull/42882"
},
{
"type": "WEB",
"url": "https://github.com/discourse/discourse/security/advisories/GHSA-8m44-f6g9-7cg7"
},
{
"type": "WEB",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-91122"
}
],
"schema_version": "1.6.2",
"summary": "Discourse: Chat MessageBus delivers read-restricted messages to unauthorized users"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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