Vulnerability-Lookup

GHSA-4VPG-GWQQ-W44C

Vulnerability from github – Published: 2026-10-02 23:05 – Updated: 2026-10-02 23:05

Summary

SiYuan: 17 block metadata/content endpoints in kernel/api/block.go have zero publish-access filtering, reachable by anonymous publish-mode readers

Details

Same CWE-862 family, found via an automated bulk sweep of every /api/block/* handler in kernel/api/block.go for the presence of any access-check reference (IsReadOnlyRoleContext, checkBlockPublishAccess, GetPublishAccess) anywhere in the function body. 17 of 28 candidate endpoints have none. Cross-checked against the file's own sibling functions (getBlockInfo, getBlockDOM, getRefIDs, etc.), which correctly implement the check, confirming this is a real, uneven gap rather than a deliberate design choice for the whole file.

Summary

17 handlers in kernel/api/block.go, all gated only by model.CheckAuth with no admin-role requirement, return block content-derived text, structural metadata, or existence information for any block ID supplied, with no access check anywhere in the handler or, for the ones checked in detail, the model functions they call. This is CWE-862 (Missing Authorization), the same class as the companion advisories from this review round, found in a different file via a systematic bulk check rather than manual inspection of each function individually.

Details

Confirmed via automated extraction of every function body between func NAME(c *gin.Context) { and the next such declaration, then searching each for any of IsReadOnlyRoleContext, checkBlockPublishAccess, GetPublishAccess, or PublishAccess. The following contain none of these, at all:

Endpoint	What it discloses
`getRefText`	The block's actual reference-display text, derived from its content, for any ID (`kernel/api/block.go:564`)
`getBlockBreadcrumb`	The block's breadcrumb/title path (`:?`)
`getBlockDefIDsByRefText`	Which block IDs a given reference text resolves to
`getRefIDsByFileAnnotationID`	Block IDs referencing a given PDF/file annotation
`getBlockIndex` / `getBlocksIndexes`	A block's position/index within its document
`getTreeStat`	Structural statistics for a document tree
`getBlocksWordCount` / `getContentWordCount`	Word/character counts for arbitrary content
`checkBlockExist` / `checkBlocksExist`	Existence oracle for any block ID
`getUnfoldedParentID`	The nearest unfolded ancestor of a block
`checkBlockFold`	Whether a block is currently folded
`getBlockSiblingID`	A block's sibling in document order
`getBlockRelevantIDs`	IDs of blocks related to a given block
`getBlockTreeInfos`	Block tree metadata for a set of IDs
`checkBlockRef`	Whether a block is referenced elsewhere

The clearest, most severe example, getRefText (POST /api/block/getRefText, kernel/api/router.go:238):

func getRefText(c *gin.Context) {
    ...
    id := arg["id"].(string)
    if util.InvalidIDPattern(id, ret) {
        return
    }
    var refText string
    if notebook, ok := arg["notebook"].(string); ok && notebook != "" && model.IsEncryptedBox(notebook) {
        refText = model.GetBlockRefTextInBox(id, notebook)
    } else {
        refText = model.GetBlockRefText(id)
    }
    ...
    ret.Data = refText
}

model.GetBlockRefText(id) resolves the actual display text used wherever this block is referenced, ordinarily derived from the block's real content, for any id in the workspace, with no scoping.

For contrast, sibling functions in the same file correctly implement the check, e.g. getRefIDs (kernel/api/router.go:235) and getBlockInfo/getBlockDOM/getBlockKramdown all contain if model.IsReadOnlyRoleContext(c) { ... } guards. This confirms the 17 above are an inconsistency within the file, not an intentional decision that the whole file is exempt from this control.

Step-by-step reproduction

# id: a block inside a document that was never published, or is
# Disable=true in publish access
curl -s -X POST http://<target>:6806/api/block/getRefText \
  -H "Content-Type: application/json" -d '{"id":"<private-block-id>"}'
# Returns the block's actual reference text with no session, no
# AccessAuthCode, no publish password.

curl -s -X POST http://<target>:6806/api/block/checkBlockExist \
  -H "Content-Type: application/json" -d '{"id":"<guessed-block-id>"}'
# Confirms or denies existence of any guessed ID workspace-wide.

Repeat against any of the other 15 endpoints in the table above, substituting their expected arguments, each returns data with no access check.

Impact

Any published SiYuan workspace discloses block-level content-derived text, structural metadata, and existence information for the entire workspace, not just published notebooks, to any anonymous internet visitor. getRefText in particular discloses real content text, not just metadata, for any block ID. The existence-oracle endpoints (checkBlockExist/checkBlockRef) combine with the companion advisory's getIDsByHPath title-guessing primitive to let an attacker efficiently probe for and confirm private content without ever needing legitimate access. ```

Affected products

Field	Value
Ecosystem	Go
Package name	`github.com/siyuan-note/siyuan/kernel`
Affected versions	Present at current HEAD (commit `eef1056`/`1673b75`, reviewed 2026-08-03)
Patched versions	(none yet, leave blank until a fix is released)

Severity

Field	Value
Vector string	`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N`
Score	7.5 (High). Network vector, low complexity, no privileges or user interaction required, high confidentiality impact via `getRefText`'s real content-text disclosure plus the combined structural/existence oracle from the other 16, no integrity/availability impact since all 17 are read-only.

Weaknesses (CWE)

CWE-862: Missing Authorization (primary)
CWE-204: Observable Response Discrepancy (contributing, via the existence-oracle endpoints)

Notes for filing

Same CWE-862 family as the two companion advisories from this review round (asset/attribute-view listing, and path/title resolution). Recommend the maintainers treat all three as one remediation pass: grep every /api/* handler for the literal presence of IsReadOnlyRoleContext and manually audit every one that lacks it, rather than fixing endpoint-by-endpoint, since the pattern has now recurred across three separate files.
Suggested fix: add if model.IsReadOnlyRoleContext(c) { ... } guards matching the pattern already correctly used by this file's own getBlockInfo/getBlockDOM/getRefIDs functions.

Severity

7.5 (High)


                  
                    CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/siyuan-note/siyuan/kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.0.0-20260804015139-bd067a4fe9b2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-74904"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-204",
      "CWE-862"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-02T23:05:33Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "Same CWE-862 family, found via an automated bulk sweep of every\n`/api/block/*` handler in `kernel/api/block.go` for the presence of any\naccess-check reference (`IsReadOnlyRoleContext`, `checkBlockPublishAccess`,\n`GetPublishAccess`) anywhere in the function body. 17 of 28 candidate\nendpoints have none. Cross-checked against the file\u0027s own sibling\nfunctions (`getBlockInfo`, `getBlockDOM`, `getRefIDs`, etc.), which\ncorrectly implement the check, confirming this is a real, uneven gap\nrather than a deliberate design choice for the whole file.\n\n\n### Summary\n17 handlers in `kernel/api/block.go`, all gated only by `model.CheckAuth`\nwith no admin-role requirement, return block content-derived text,\nstructural metadata, or existence information for any block ID supplied,\nwith no access check anywhere in the handler or, for the ones checked in\ndetail, the model functions they call. This is CWE-862 (Missing\nAuthorization), the same class as the companion advisories from this\nreview round, found in a different file via a systematic bulk check\nrather than manual inspection of each function individually.\n\n### Details\nConfirmed via automated extraction of every function body between\n`func NAME(c *gin.Context) {` and the next such declaration, then\nsearching each for any of `IsReadOnlyRoleContext`,\n`checkBlockPublishAccess`, `GetPublishAccess`, or `PublishAccess`. The\nfollowing contain none of these, at all:\n\n| Endpoint | What it discloses |\n|---|---|\n| `getRefText` | The block\u0027s actual reference-display text, derived from its content, for any ID (`kernel/api/block.go:564`) |\n| `getBlockBreadcrumb` | The block\u0027s breadcrumb/title path (`:?`) |\n| `getBlockDefIDsByRefText` | Which block IDs a given reference text resolves to |\n| `getRefIDsByFileAnnotationID` | Block IDs referencing a given PDF/file annotation |\n| `getBlockIndex` / `getBlocksIndexes` | A block\u0027s position/index within its document |\n| `getTreeStat` | Structural statistics for a document tree |\n| `getBlocksWordCount` / `getContentWordCount` | Word/character counts for arbitrary content |\n| `checkBlockExist` / `checkBlocksExist` | Existence oracle for any block ID |\n| `getUnfoldedParentID` | The nearest unfolded ancestor of a block |\n| `checkBlockFold` | Whether a block is currently folded |\n| `getBlockSiblingID` | A block\u0027s sibling in document order |\n| `getBlockRelevantIDs` | IDs of blocks related to a given block |\n| `getBlockTreeInfos` | Block tree metadata for a set of IDs |\n| `checkBlockRef` | Whether a block is referenced elsewhere |\n\nThe clearest, most severe example, `getRefText`\n(`POST /api/block/getRefText`, `kernel/api/router.go:238`):\n```go\nfunc getRefText(c *gin.Context) {\n    ...\n    id := arg[\"id\"].(string)\n    if util.InvalidIDPattern(id, ret) {\n        return\n    }\n    var refText string\n    if notebook, ok := arg[\"notebook\"].(string); ok \u0026\u0026 notebook != \"\" \u0026\u0026 model.IsEncryptedBox(notebook) {\n        refText = model.GetBlockRefTextInBox(id, notebook)\n    } else {\n        refText = model.GetBlockRefText(id)\n    }\n    ...\n    ret.Data = refText\n}\n```\n`model.GetBlockRefText(id)` resolves the actual display text used\nwherever this block is referenced, ordinarily derived from the block\u0027s\nreal content, for any `id` in the workspace, with no scoping.\n\nFor contrast, sibling functions in the same file correctly implement\nthe check, e.g. `getRefIDs` (`kernel/api/router.go:235`) and\n`getBlockInfo`/`getBlockDOM`/`getBlockKramdown` all contain\n`if model.IsReadOnlyRoleContext(c) { ... }` guards. This confirms the\n17 above are an inconsistency within the file, not an intentional\ndecision that the whole file is exempt from this control.\n\n### Step-by-step reproduction\n```bash\n# id: a block inside a document that was never published, or is\n# Disable=true in publish access\ncurl -s -X POST http://\u003ctarget\u003e:6806/api/block/getRefText \\\n  -H \"Content-Type: application/json\" -d \u0027{\"id\":\"\u003cprivate-block-id\u003e\"}\u0027\n# Returns the block\u0027s actual reference text with no session, no\n# AccessAuthCode, no publish password.\n\ncurl -s -X POST http://\u003ctarget\u003e:6806/api/block/checkBlockExist \\\n  -H \"Content-Type: application/json\" -d \u0027{\"id\":\"\u003cguessed-block-id\u003e\"}\u0027\n# Confirms or denies existence of any guessed ID workspace-wide.\n```\nRepeat against any of the other 15 endpoints in the table above,\nsubstituting their expected arguments, each returns data with no\naccess check.\n\n### Impact\nAny published SiYuan workspace discloses block-level content-derived\ntext, structural metadata, and existence information for the *entire*\nworkspace, not just published notebooks, to any anonymous internet\nvisitor. `getRefText` in particular discloses real content text, not\njust metadata, for any block ID. The existence-oracle endpoints\n(`checkBlockExist`/`checkBlockRef`) combine with the companion\nadvisory\u0027s `getIDsByHPath` title-guessing primitive to let an attacker\nefficiently probe for and confirm private content without ever needing\nlegitimate access.\n```\n\n## Affected products\n\n| Field | Value |\n|---|---|\n| Ecosystem | **Go** |\n| Package name | `github.com/siyuan-note/siyuan/kernel` |\n| Affected versions | Present at current HEAD (commit `eef1056`/`1673b75`, reviewed 2026-08-03) |\n| Patched versions | *(none yet, leave blank until a fix is released)* |\n\n## Severity\n\n| Field | Value |\n|---|---|\n| Vector string | `CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N` |\n| Score | **7.5 (High)**. Network vector, low complexity, no privileges or user interaction required, high confidentiality impact via `getRefText`\u0027s real content-text disclosure plus the combined structural/existence oracle from the other 16, no integrity/availability impact since all 17 are read-only. |\n\n## Weaknesses (CWE)\n\n- **CWE-862**: Missing Authorization (primary)\n- **CWE-204**: Observable Response Discrepancy (contributing, via the existence-oracle endpoints)\n\n## Notes for filing\n- Same CWE-862 family as the two companion advisories from this review\n  round (asset/attribute-view listing, and path/title resolution).\n  Recommend the maintainers treat all three as one remediation pass:\n  grep every `/api/*` handler for the literal presence of\n  `IsReadOnlyRoleContext` and manually audit every one that lacks it,\n  rather than fixing endpoint-by-endpoint, since the pattern has now\n  recurred across three separate files.\n- Suggested fix: add `if model.IsReadOnlyRoleContext(c) { ... }` guards\n  matching the pattern already correctly used by this file\u0027s own\n  `getBlockInfo`/`getBlockDOM`/`getRefIDs` functions.",
  "id": "GHSA-4vpg-gwqq-w44c",
  "modified": "2026-10-02T23:05:33Z",
  "published": "2026-10-02T23:05:33Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/security/advisories/GHSA-4vpg-gwqq-w44c"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74904"
    },
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/commit/bd067a4fe9b208c0858d8d9dc6220dc8affc403e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/siyuan-note/siyuan"
    },
    {
      "type": "WEB",
      "url": "https://github.com/siyuan-note/siyuan/releases/tag/v3.8.0"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/siyuan-before-missing-authorization-via-block-api"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "SiYuan: 17 block metadata/content endpoints in kernel/api/block.go have zero publish-access filtering, reachable by anonymous publish-mode readers"
}

CVE-2026-74904 (GCVE-0-2026-74904)

Vulnerability from cvelistv5 – Published: 2026-08-18 11:19 – Updated: 2026-08-18 15:04

Title

SiYuan before v3.7.4 Missing Authorization via block API

Summary

SiYuan before v3.7.4 is missing authorization checks in 17 block metadata/content endpoints in kernel/api/block.go (including getRefText, checkBlockExist, and getBlockBreadcrumb). These handlers are gated only by basic authentication (model.CheckAuth) and lack publish-access filtering, allowing anonymous publish-mode readers to disclose private block content-derived text, structural metadata, and existence information for arbitrary block IDs across the workspace.

Severity

8.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

7.5 (High)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-08-18 15:04 UTC

CWE

CWE-862 - Missing Authorization

Assigner

VulnCheck mitre root Scorecard

References

2 references

URL	Tags
https://github.com/siyuan-note/siyuan/security/ad…	vendor-advisory
https://www.vulncheck.com/advisories/siyuan-befor…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
siyuan-note	siyuan	Affected: 0 , < 3.7.4 (semver) Unaffected: 3.7.4 (semver) cpe:2.3:a:b3log:siyuan::::::::

Date Public

2026-08-04 00:00

Credits

alham-rizvi

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-74904",
                "options": [
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                "role": "CISA Coordinator",
                "timestamp": "2026-08-18T15:04:37.400477Z",
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Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-4VPG-GWQQ-W44C

Summary

Details

Step-by-step reproduction

Impact

Affected products

Severity

Weaknesses (CWE)

Notes for filing

CVE-2026-74904 (GCVE-0-2026-74904)

Tags

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