Medium
Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing
Type: advisorySources: OSV
Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.format_for_email because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and hashtag data-slug values can cause decoded attribute text to be reinterpreted as HTML. The vulnerable conversion also fails to strictly validate the Vimeo iframe host and path, allowing non-Vimeo allowlisted iframes to be converted. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-72720
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 15:50 UTC · Revision 1
Source evidence
Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing
core-osv · Original sourcePublished 10 Aug 2026, 15:41 UTC
Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.format_for_email because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and hashtag data-slug values can cause decoded attribute text to be reinterpreted as HTML. The vulnerable conversion also fails to strictly validate the Vimeo iframe host and path, allowing non-Vimeo allowlisted iframes to be converted. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1.
osv:CVE-2026-72720
Complete source record
{
"id": "ed65500c0954c528f41a4321ecf4ecfa1f5cbbe76bcd6cc09a52dac4ac995570",
"url": "https://osv.dev/vulnerability/CVE-2026-72720",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Discourse: HTML injection in PrettyText.format_for_email from cooked-attribute reparsing",
"summary": "Discourse is an open-source discussion platform. Prior to 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1, Discourse has HTML injection in PrettyText.format_for_email because cooked attribute values are reparsed as markup. Crafted Vimeo iframe sources, secure-upload URLs or dimensions, and hashtag data-slug values can cause decoded attribute text to be reinterpreted as HTML. The vulnerable conversion also fails to strictly validate the Vimeo iframe host and path, allowing non-Vimeo allowlisted iframes to be converted. This issue is fixed in versions 2026.1.7, 2026.6.2, 2026.7.1, and 2026.8.0-latest.1.",
"evidence": "osv:CVE-2026-72720",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-72720",
"aliases": [
"BIT-discourse-2026-72720",
"CVE-2026-72720",
"GHSA-3q6f-6gm9-m35v"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N"
}
],
"affected": [
{
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"repo": "https://github.com/discourse/discourse",
"type": "GIT",
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],
"modified": "2026-10-28T02:30:36.833803486Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72720.json",
"https://github.com/discourse/discourse/security/advisories/GHSA-3q6f-6gm9-m35v",
"https://nvd.nist.gov/vuln/detail/CVE-2026-72720",
"https://github.com/discourse/discourse/commit/234ee88a5b9b53bf938c53351eab20130323485f",
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"https://github.com/discourse/discourse/pull/42244",
"https://github.com/discourse/discourse/pull/42245",
"https://github.com/discourse/discourse/pull/42246",
"https://github.com/discourse/discourse/pull/42247"
],
"provider_metadata": {
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],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72720.json"
}
},
"related_cves": [
{
"value": "CVE-2026-72720",
"evidence": "/id"
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],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 504296,
"published_at": "2026-08-10T15:41:51.764+00:00"
}