WeRSS (we-mp-rss) through 1.5.3 RCE via template Parameter in /rss Endpoint

{
  "id": "1553e14540c1d7504cbea4104b62aefe06619275f0a993b78fe86beb3a9daf65",
  "url": "https://osv.dev/vulnerability/CVE-2026-111687",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "WeRSS (we-mp-rss) through 1.5.3 RCE via template Parameter in /rss Endpoint",
    "summary": "WeRSS (we-mp-rss) through 1.5.3 contains a remote code execution vulnerability that allows unauthenticated attackers to run code via the template parameter of the public GET /rss/{feed_id} endpoint. Attackers can supply a non-built-in ext value and a {{=expression}} template whose object-subclass traversal bypasses the eval denylist to run OS commands as the service account.",
    "evidence": "osv:CVE-2026-111687",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-111687",
      "aliases": [
        "CVE-2026-111687"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/rachelos/we-mp-rss",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "bb29a7a45e516d26cf434c6f349404ff18413727"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.5.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.5.3"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.5.3",
            "v1.5.2",
            "v1.5.1",
            "v1.5.0",
            "v1.4.9"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-111687.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:33.602006307Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/111xxx/CVE-2026-111687.json",
        "https://hackmd.io/@hieuPenguinnn/werss-rss-template-unauth-ssti-rce",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-111687",
        "https://www.vulncheck.com/advisories/werss-we-mp-rss-through-1.5.3-rce-via-template-parameter-in-rss-endpoint",
        "https://github.com/rachelos/we-mp-rss",
        "https://github.com/rachelos/we-mp-rss/blob/v1.5.3/apis/rss.py#L185-L198",
        "https://github.com/rachelos/we-mp-rss/blob/v1.5.3/core/lax/template_parser.py#L1150-L1166"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-95"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/111xxx/CVE-2026-111687.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-111687",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 501038,
  "published_at": "2026-10-16T17:39:44.866+00:00"
}