Vulnerability-Lookup

GHSA-53WH-3R96-488V

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

Details

Shepherd (shepherd-ai) through 0.3.1 contains a server-side request forgery guard bypass in the citation-checker extra because the public_url guard validates a resolved address but fetch re-resolves the hostname at connect time. Attackers who plant a crafted reference URL in a checked document and control its DNS can rebind it to internal addresses, sending GET requests to internal HTTP(S) services and capturing responses in evidence files.

Severity

3.1 (Low)


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

2.3 (Low)


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

Show details on source website

JSON

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{
  "affected": [],
  "aliases": [
    "CVE-2026-108741"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-367"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-10-11T13:17:18Z",
    "severity": "LOW"
  },
  "details": "Shepherd (shepherd-ai) through 0.3.1 contains a server-side request forgery guard bypass in the citation-checker extra because the public_url guard validates a resolved address but fetch re-resolves the hostname at connect time. Attackers who plant a crafted reference URL in a checked document and control its DNS can rebind it to internal addresses, sending GET requests to internal HTTP(S) services and capturing responses in evidence files.",
  "id": "GHSA-53wh-3r96-488v",
  "modified": "2026-10-11T15:31:05Z",
  "published": "2026-10-11T15:31:05Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-108741"
    },
    {
      "type": "WEB",
      "url": "https://github.com/shepherd-agents/shepherd"
    },
    {
      "type": "WEB",
      "url": "https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/fetch.py#L34-L55"
    },
    {
      "type": "WEB",
      "url": "https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/network.py#L9-L17"
    },
    {
      "type": "WEB",
      "url": "https://hackmd.io/@haind03/shepherd-citation-checker-dns-rebinding-ssrf"
    },
    {
      "type": "WEB",
      "url": "https://www.vulncheck.com/advisories/shepherd-through-0.3.1-ssrf-via-dns-rebinding-in-citation-checker"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/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-2026-108741 (GCVE-0-2026-108741)

Vulnerability from cvelistv5 – Published: 2026-10-11 12:19 – Updated: 2026-10-11 12:19

Title

Shepherd through 0.3.1 SSRF via DNS Rebinding in Citation Checker

Summary

Severity

2.3 (Low)


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

3.1 (Low)


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

CWE

CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition

Assigner

VulnCheck CNA under the mitre root

CNA scorecard B 84/100 over 5496 records in the last 180 days details

References

5 references

URL	Tags
https://hackmd.io/@haind03/shepherd-citation-chec…	third-party-advisory
https://github.com/shepherd-agents/shepherd/blob/…	technical-description
https://github.com/shepherd-agents/shepherd/blob/…	technical-description
https://github.com/shepherd-agents/shepherd	product
https://www.vulncheck.com/advisories/shepherd-thr…	third-party-advisory

Impacted products

1 product

Vendor	Product	Version
shepherd-agents	Shepherd	Affected: 0 , ≤ 0.3.1 (semver)

Date Public

2026-10-10 00:00

Credits

HaiND from the Post and Telecommunication Institute of Technology

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "collectionURL": "https://pypi.org",
          "defaultStatus": "unaffected",
          "packageURL": "pkg:pypi/shepherd-ai",
          "product": "Shepherd",
          "repo": "https://github.com/shepherd-agents/shepherd",
          "vendor": "shepherd-agents",
          "versions": [
            {
              "lessThanOrEqual": "0.3.1",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "HaiND from the Post and Telecommunication Institute of Technology"
        }
      ],
      "datePublic": "2026-10-10T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Shepherd (shepherd-ai) through 0.3.1 contains a server-side request forgery guard bypass in the citation-checker extra because the public_url guard validates a resolved address but fetch re-resolves the hostname at connect time. Attackers who plant a crafted reference URL in a checked document and control its DNS can rebind it to internal addresses, sending GET requests to internal HTTP(S) services and capturing responses in evidence files."
        }
      ],
      "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:L/VI:N/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "LOW",
            "vulnIntegrityImpact": "NONE"
          },
          "format": "CVSS"
        },
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 3.1,
            "baseSeverity": "LOW",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N",
            "version": "3.1"
          },
          "format": "CVSS"
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-367",
              "description": "Time-of-check Time-of-use (TOCTOU) Race Condition",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-11T12:19:45.494Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://hackmd.io/@haind03/shepherd-citation-checker-dns-rebinding-ssrf"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/network.py#L9-L17"
        },
        {
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/shepherd-agents/shepherd/blob/d34d5ca334871dfcb5a3dc76dd78045829fa4e56/shepherd/extras/citation-checker/src/shepherd_citation_checker/_engine/fetch.py#L34-L55"
        },
        {
          "tags": [
            "product"
          ],
          "url": "https://github.com/shepherd-agents/shepherd"
        },
        {
          "name": "VulnCheck Advisory: Shepherd through 0.3.1 SSRF via DNS Rebinding in Citation Checker",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/shepherd-through-0.3.1-ssrf-via-dns-rebinding-in-citation-checker"
        }
      ],
      "title": "Shepherd through 0.3.1 SSRF via DNS Rebinding in Citation Checker",
      "x_generator": {
        "engine": "vulncheck-endgame"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2026-108741",
    "datePublished": "2026-10-11T12:19:45.494Z",
    "dateReserved": "2026-10-11T01:52:55.363Z",
    "dateUpdated": "2026-10-11T12:19:45.494Z",
    "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.

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-53WH-3R96-488V

CVE-2026-108741 (GCVE-0-2026-108741)

Tags

Sightings

Nomenclature

Related by attack behaviour