Discourse: Reject literal backslash path separators in iframe src traversal guard
Discourse is an open-source discussion platform. Prior to 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0, the iframe src traversal guard did not treat literal backslashes as path separators after decoded dot segments. A crafted source could therefore pass an allowed_iframes subpath check while browser URL normalization moved the iframe outside the intended allowed path. The resulting iframe could load content from a location that the administrator did not allow. This issue is fixed in versions 2026.1.8, 2026.6.3, 2026.7.2, and 2026.8.0.
BIT-discourse-2026-91123
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: osv:BIT-discourse-2026-91123
discourse
Source reference: /affected/0/package/name
- Affected versions
- Not stated in this record
- Fixed versions
- 2026.8.0
Source reference:
/affected/0/ranges - Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"ranges": [
{
"type": "SEMVER",
"events": [
{
"introduced": "0"
},
{
"fixed": "2026.8.0"
}
]
}
],
"package": {
"name": "discourse",
"purl": "pkg:bitnami/discourse",
"ecosystem": "Bitnami"
},
"severity": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N"
}
],
"database_specific": {
"source": "https://github.com/bitnami/vulndb/tree/main/data/discourse/BIT-discourse-2026-91123.json"
}
}
]- Related CVEs
- CVE-2026-91123
Source reference:
/aliases
Publisher severity
high
Source reference: /database_specific/severity
- Event
- #59611 · Revision 1
- Added to Heist Feed
- Publisher date