Vikunja: Planka migration retains an unbounded aggregate of attacker-served attachments and can OOM the API

{
  "id": "06d1fbe5dc447aa50a331c1d6e0bb49007a797f675b3f324f4030b1cb723d643",
  "url": "https://osv.dev/vulnerability/GHSA-wq92-8x3r-fm38",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Vikunja: Planka migration retains an unbounded aggregate of attacker-served attachments and can OOM the API",
    "summary": "# Planka migration retains an unbounded aggregate of attacker-served attachments and can OOM the API ## Summary The always-registered Planka migration lets any ordinary user select a Planka server. Although Vikunja caps each JSON response, pagination loop, and attachment independently, it has no aggregate job budget. The conversion stage downloads every advertised non-link attachment and keeps every byte slice live until the complete hierarchy is inserted. A public attacker server can therefore drive memory beyond any finite service allocation. The final Docker run preserved default SSRF policy and OOM-killed the healthy API after five individually valid 20 MiB attachment responses. ## Impact and affected scope - **Type:** Resource Exhaustion Dos - **Affected component:** POST /api/v2/migration/planka/migrate; Asynchronous migration.requested worker for the Planka migrator - **Preconditions:** A low-privilege Vikunja user supplies an attacker-operated public Planka URL and token. That server controls project/board/card/attachment counts and streams each attachment body at or below Vikunja's normal per-file limit. - **Verified revision:** `d66ef3d1a39c6f7289593059a1a34afd1d059260` on 28 August 2026 - **Affected release range:** `> 2.5.0` for the tested post-2.5.0 main branch; no released build was independently reproduced A low-privilege remote user operating a public HTTP server can terminate the shared Vikunja process and make the API unavailable with one migration submissio",
    "evidence": "osv:GHSA-wq92-8x3r-fm38",
    "products": [
      {
        "name": {
          "value": "code.vikunja.io/api",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2.6.0",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "GHSA-wq92-8x3r-fm38",
      "aliases": [
        "CVE-2026-91970",
        "GHSA-wq92-8x3r-fm38",
        "GO-2026-6757"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "SEMVER",
              "events": [
                {
                  "introduced": "2.5.0"
                },
                {
                  "fixed": "2.6.0"
                }
              ]
            }
          ],
          "package": {
            "name": "code.vikunja.io/api",
            "purl": "pkg:golang/code.vikunja.io/api",
            "ecosystem": "Go"
          },
          "database_specific": {
            "source": "https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/10/GHSA-wq92-8x3r-fm38/GHSA-wq92-8x3r-fm38.json"
          }
        }
      ],
      "modified": "2026-10-19T21:41:00.503878989Z",
      "provider": "osv",
      "references": [
        "https://github.com/go-vikunja/vikunja/security/advisories/GHSA-wq92-8x3r-fm38",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-91970",
        "https://github.com/go-vikunja/vikunja/pull/3688",
        "https://github.com/go-vikunja/vikunja",
        "https://github.com/go-vikunja/vikunja/releases/tag/v2.6.0",
        "https://www.vulncheck.com/advisories/vikunja-before-2.6.0-resource-exhaustion-via-planka-migration"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-770"
        ],
        "severity": "HIGH",
        "github_reviewed": true,
        "nvd_published_at": null,
        "github_reviewed_at": "2026-10-09T20:53:24Z"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-91970",
        "evidence": "/aliases"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/database_specific/severity"
  },
  "source_id": "core-osv",
  "document_id": 376766,
  "published_at": "2026-10-09T20:53:24+00:00"
}