High
Discourse: Remote code execution via pdf uploads
Type: advisorySources: OSV
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, under certain non-default configurations, processing of PDF uploads could be exploited to obtain RCE on the server. This issue is patched in 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-55420
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 4 Nov 2026, 15:29 UTC · Revision 1
Source evidence
Discourse: Remote code execution via pdf uploads
core-osv · Original sourcePublished 9 Jul 2026, 17:54 UTC
Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, under certain non-default configurations, processing of PDF uploads could be exploited to obtain RCE on the server. This issue is patched in 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.
osv:CVE-2026-55420
Complete source record
{
"id": "dbcc7e48a6c880967d2fa334275e43f93ca85048f7169d64e0cb369e0607ebe7",
"url": "https://osv.dev/vulnerability/CVE-2026-55420",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Discourse: Remote code execution via pdf uploads",
"summary": "Discourse is an open-source discussion platform. Prior to 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5, under certain non-default configurations, processing of PDF uploads could be exploited to obtain RCE on the server. This issue is patched in 2026.6.0, 2026.5.1, 2026.4.2, and 2026.1.5.",
"evidence": "osv:CVE-2026-55420",
"products": [],
"severity": "high",
"structured": {
"id": "CVE-2026-55420",
"aliases": [
"BIT-discourse-2026-55420",
"CVE-2026-55420",
"GHSA-7wq5-jgww-5rw3"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/discourse/discourse",
"type": "GIT",
"events": [
{
"introduced": "322d3c0ac6a8f133b3f82875e9dbbe310f638c1b"
},
{
"fixed": "c06899647d758493d95a5b301e573ffa3db1e878"
},
{
"introduced": "fdd750d960e603415db62242eca3c30d68e366db"
},
{
"fixed": "4bbdddfc6700ca23604242111d4fa0e00347af97"
},
{
"introduced": "640840d818f4ee9375829ece0ef452923bb0c012"
},
{
"fixed": "598586ccf2e046a25d4b54132e4e1feb47f24e98"
},
{
"introduced": "06d03da34c4ed09ea59f917f045ba250d2b6320d"
},
{
"fixed": "ca5a7e06167561928556afa2f237d67e459c6914"
},
{
"fixed": "06d03da34c4ed09ea59f917f045ba250d2b6320d"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "2026.1.0"
},
{
"fixed": "2026.1.5"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "2026.4.0"
},
{
"fixed": "2026.4.2"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "2026.5.0"
},
{
"fixed": "2026.5.1"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:discourse:discourse:2026.6.0:*:*:*:latest:*:*:*",
"range": [
{
"introduced": "2026.6.0"
},
{
"last_affected": "2026.6.0"
}
],
"source": "CPE_STRING"
},
{
"range": [
{
"fixed": "ca5a7e06167561928556afa2f237d67e459c6914"
}
],
"source": "REFERENCES_COMMIT"
},
{
"range": [
{
"fixed": "c06899647d758493d95a5b301e573ffa3db1e878"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v2026.1.5"
},
{
"range": [
{
"fixed": "4bbdddfc6700ca23604242111d4fa0e00347af97"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v2026.4.2"
},
{
"range": [
{
"fixed": "598586ccf2e046a25d4b54132e4e1feb47f24e98"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v2026.5.1"
},
{
"range": [
{
"fixed": "06d03da34c4ed09ea59f917f045ba250d2b6320d"
}
],
"source": "REFERENCES_TAG",
"original_tag": "v2026.6.0"
}
]
}
}
],
"versions": [
"2026.6.0",
"v2026.5.0",
"v2026.1.4",
"v2026.4.1",
"v2026.5.0-latest.1",
"v2026.4.0",
"v2026.5.0-latest",
"v2026.1.3",
"v2026.4.0-latest",
"v2026.1.2",
"v2026.1.1",
"v2026.1.0",
"stable",
"esr",
"v2026.1.0-latest"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-55420.json"
}
}
],
"modified": "2026-10-28T02:30:37.042758241Z",
"provider": "osv",
"references": [
"https://github.com/discourse/discourse/releases/tag/v2026.1.5",
"https://github.com/discourse/discourse/releases/tag/v2026.4.2",
"https://github.com/discourse/discourse/releases/tag/v2026.5.1",
"https://github.com/discourse/discourse/releases/tag/v2026.6.0",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55420.json",
"https://github.com/discourse/discourse/security/advisories/GHSA-7wq5-jgww-5rw3",
"https://nvd.nist.gov/vuln/detail/CVE-2026-55420",
"https://github.com/discourse/discourse/commit/ca5a7e06167561928556afa2f237d67e459c6914"
],
"provider_metadata": {
"cwe_ids": [
"CWE-78"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/55xxx/CVE-2026-55420.json"
}
},
"related_cves": [
{
"value": "CVE-2026-55420",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 504132,
"published_at": "2026-07-09T17:54:07.94+00:00"
}