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Critical

Security advisory

Type: advisorySources: OSVCVE: CVE-2025-9556

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

CVE-2025-9556

core-osv · Original source

Published 12 Sept 2025, 13:45 UTC

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"
}