Vulnerability-Lookup

GHSA-8C39-3R7M-GWC4

Vulnerability from github – Published: 2026-10-11 15:31 – Updated: 2026-10-11 15:31

Details

thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges.

Severity

4.2 (Medium)


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

2.3 (Low)


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

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-108839"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-59"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-11T14:17:04Z",
    "severity": "LOW"
  },
  "details": "thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges.",
  "id": "GHSA-8c39-3r7m-gwc4",
  "modified": "2026-10-11T15:31:07Z",
  "published": "2026-10-11T15:31:07Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-108839"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thClaws/thClaws"
    },
    {
      "type": "WEB",
      "url": "https://github.com/thClaws/thClaws/blob/v0.141.0/crates/core/src/api_v1/artifacts.rs#L335-L420"
    },
    {
      "type": "WEB",
      "url": "https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/thclaws-api-inputs-symlink-escape"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/thclaws-through-0.141.0-symlink-following-file-write-via-post-v1-inputs"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-108839 (GCVE-0-2026-108839)

Vulnerability from cvelistv5 – Published: 2026-10-11 13:26 – Updated: 2026-10-11 13:26

Title

thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs

Summary

Severity

2.3 (Low)


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

4.2 (Medium)


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

CWE

CWE-59 - Improper Link Resolution Before File Access ('Link Following')

Assigner

VulnCheck CNA under the mitre root

CNA scorecard B 84/100 over 6045 records in the last 180 days details

References

4 references

URL	Tags
https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/thclaws…	third-party-advisory
https://github.com/thClaws/thClaws/blob/v0.141.0/…	technical-description
https://github.com/thClaws/thClaws	product
https://www.vulncheck.com/advisories/thclaws-thro…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
thClaws	thClaws	Affected: 0 , ≤ 0.141.0 (semver)

Date Public

2026-10-11 00:00

Credits

hieuPenguinnn

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:github/thClaws/thClaws",
          "product": "thClaws",
          "repo": "https://github.com/thClaws/thClaws",
          "vendor": "thClaws",
          "versions": [
            {
              "lessThanOrEqual": "0.141.0",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "hieuPenguinnn"
        }
      ],
      "datePublic": "2026-10-11T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "thClaws through 0.141.0 contains a link-following vulnerability in the post_inputs handler of the v1 API POST /v1/inputs endpoint that allows writes outside the workspace by following symlinks. Attackers who plant a symlink under the allowed inputs/ prefix can cause later authenticated uploads to write or truncate files outside the workspace with daemon privileges."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 2.3,
            "baseSeverity": "LOW",
            "privilegesRequired": "NONE",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "PASSIVE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "LOW",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "LOW"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 4.2,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "NONE",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:L",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-59",
              "description": "Improper Link Resolution Before File Access (\u0027Link Following\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-11T13:26:00.141Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://hackmd.io/@1ExmmukzRMWN7B4gQ4W-4Q/thclaws-api-inputs-symlink-escape"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/thClaws/thClaws/blob/v0.141.0/crates/core/src/api_v1/artifacts.rs#L335-L420"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/thClaws/thClaws"
        },
        {
          "name": "VulnCheck Advisory: thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/thclaws-through-0.141.0-symlink-following-file-write-via-post-v1-inputs"
        }
      ],
      "title": "thClaws through 0.141.0 Symlink Following File Write via POST /v1/inputs",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-108839",
    "datePublished": "2026-10-11T13:26:00.141Z",
    "dateReserved": "2026-10-11T12:50:50.838Z",
    "dateUpdated": "2026-10-11T13:26:00.141Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

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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.

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