Critical
Security advisory
Langchaingo supports the use of jinja2 syntax when parsing prompts, which is in turn parsed using the gonja library v1.5.3. Gonja supports include and extends syntax to read files, which leads to a server side template injection vulnerability within langchaingo, allowing an attacker to insert a statement into a prompt to read the "etc/passwd" file.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2025-9556
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 03:09 UTC · Revision 1
Source evidence
Langchaingo supports the use of jinja2 syntax when parsing prompts, which is in turn parsed using the gonja library v1.5.3. Gonja supports include and extends syntax to read files, which leads to a server side template injection vulnerability within langchaingo, allowing an attacker to insert a statement into a prompt to read the "etc/passwd" file.
osv:CVE-2025-9556
Complete source record
{
"id": "a71a39340ae1566d9ab2c0629f5e39d33c6c5bfa7fda0c1d6ec271dbd2ab1579",
"url": "https://osv.dev/vulnerability/CVE-2025-9556",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2025-9556",
"summary": "Langchaingo supports the use of jinja2 syntax when parsing prompts, which is in turn parsed using the gonja library v1.5.3. Gonja supports include and extends syntax to read files, which leads to a server side template injection vulnerability within langchaingo, allowing an attacker to insert a statement into a prompt to read the \"etc/passwd\" file.",
"evidence": "osv:CVE-2025-9556",
"products": [],
"severity": "critical",
"structured": {
"id": "CVE-2025-9556",
"aliases": [
"CVE-2025-9556",
"GHSA-mgcj-g55g-rf6h"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/tmc/langchaingo",
"type": "GIT",
"events": [
{
"introduced": "509308ff01c13e662d5613d3aea793fabe18edd2"
},
{
"last_affected": "509308ff01c13e662d5613d3aea793fabe18edd2"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0.1.14"
},
{
"last_affected": "0.1.14"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandaloneSingleVersion"
}
]
}
}
],
"versions": [
"0.1.14",
"v0.1.14"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-9556.json"
}
}
],
"modified": "2026-10-28T02:30:49.197854913Z",
"provider": "osv",
"references": [
"https://www.kb.cert.org/vuls/id/949137",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/9xxx/CVE-2025-9556.json",
"https://github.com/tmc/langchaingo/security/advisories/GHSA-mgcj-g55g-rf6h",
"https://nvd.nist.gov/vuln/detail/CVE-2025-9556",
"https://github.com/tmc/langchaingo/pull/1348"
],
"provider_metadata": {
"cna_assigner": "certcc",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/9xxx/CVE-2025-9556.json"
}
},
"related_cves": [
{
"value": "CVE-2025-9556",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 517633,
"published_at": "2025-09-12T13:45:14.684+00:00"
}