Vulnerability-Lookup

FKIE_CVE-2026-42261

Vulnerability from fkie_nvd - Published: 2026-05-08 04:16 - Updated: 2026-06-17 10:47

Severity

7.1 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N

Summary

PromptHub is an all-in-one AI toolbox for prompt, skill, and agent management. From version 0.4.9 to before version 0.5.4, apps/web/src/routes/skills.ts exposes an authenticated endpoint POST /api/skills/fetch-remote that fetches a user-supplied URL server-side and reflects the response body (up to 5 MB) back to the caller. The SSRF protection in apps/web/src/utils/remote-http.ts (isPrivateIPv6) attempts to block private/loopback destinations, but multiple alternate-but-valid IPv6 representations bypass the check. The bypasses reach any IPv4 address (loopback, RFC1918, link-local) via IPv4-mapped IPv6 in hex form, and the canonical ::1 via any representation that isn't the literal string "::1". Any authenticated user (role: user or admin) can trigger the SSRF. On deployments configured with ALLOW_REGISTRATION=true — a supported and documented configuration — this means any internet user who can register. This issue has been patched in version 0.5.4.

References

URL	Tags
security-advisories@github.com	https://github.com/legeling/PromptHub/releases/tag/v0.5.4	Patch, Product
security-advisories@github.com	https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6	Exploit, Mitigation, Vendor Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0	https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6	Exploit, Mitigation, Vendor Advisory

Impacted products

	Vendor	Product	Version
	legeling	prompthub	*

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "PromptHub",
          "vendor": "legeling",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.4.9, \u003c 0.5.4"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:legeling:prompthub:*:*:*:*:-:*:*:*",
              "matchCriteriaId": "70AA7323-FB30-4401-9F87-B09372E70663",
              "versionEndExcluding": "0.5.4",
              "versionStartIncluding": "0.4.9",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "PromptHub is an all-in-one AI toolbox for prompt, skill, and agent management. From version 0.4.9 to before version 0.5.4, apps/web/src/routes/skills.ts exposes an authenticated endpoint POST /api/skills/fetch-remote that fetches a user-supplied URL server-side and reflects the response body (up to 5 MB) back to the caller. The SSRF protection in apps/web/src/utils/remote-http.ts (isPrivateIPv6) attempts to block private/loopback destinations, but multiple alternate-but-valid IPv6 representations bypass the check. The bypasses reach any IPv4 address (loopback, RFC1918, link-local) via IPv4-mapped IPv6 in hex form, and the canonical ::1 via any representation that isn\u0027t the literal string \"::1\". Any authenticated user (role: user or admin) can trigger the SSRF. On deployments configured with ALLOW_REGISTRATION=true \u2014 a supported and documented configuration \u2014 this means any internet user who can register. This issue has been patched in version 0.5.4."
    }
  ],
  "id": "CVE-2026-42261",
  "lastModified": "2026-06-17T10:47:36.007",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 4.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-42261",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-05-11T18:10:25.854871Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-08T04:16:20.107",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Patch",
        "Product"
      ],
      "url": "https://github.com/legeling/PromptHub/releases/tag/v0.5.4"
    },
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Mitigation",
        "Vendor Advisory"
      ],
      "url": "https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Analyzed",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        },
        {
          "lang": "en",
          "value": "CWE-693"
        },
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}

CVE-2026-42261 (GCVE-0-2026-42261)

Vulnerability from cvelistv5 – Published: 2026-05-08 03:11 – Updated: 2026-05-11 18:11

Title

PromptHub: Authenticated SSRF via IPv6 filter bypass in `POST /api/skills/fetch-remote`

Summary

Severity

7.1 (High)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-11 18:10 UTC

CWE

CWE-20 - Improper Input Validation
CWE-693 - Protection Mechanism Failure
CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/legeling/PromptHub/security/ad…	x_refsource_CONFIRM
https://github.com/legeling/PromptHub/releases/ta…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
legeling	PromptHub	Affected: >= 0.4.9, < 0.5.4

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-42261",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-11T18:10:25.854871Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-11T18:11:16.696Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "PromptHub",
          "vendor": "legeling",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.4.9, \u003c 0.5.4"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "PromptHub is an all-in-one AI toolbox for prompt, skill, and agent management. From version 0.4.9 to before version 0.5.4, apps/web/src/routes/skills.ts exposes an authenticated endpoint POST /api/skills/fetch-remote that fetches a user-supplied URL server-side and reflects the response body (up to 5 MB) back to the caller. The SSRF protection in apps/web/src/utils/remote-http.ts (isPrivateIPv6) attempts to block private/loopback destinations, but multiple alternate-but-valid IPv6 representations bypass the check. The bypasses reach any IPv4 address (loopback, RFC1918, link-local) via IPv4-mapped IPv6 in hex form, and the canonical ::1 via any representation that isn\u0027t the literal string \"::1\". Any authenticated user (role: user or admin) can trigger the SSRF. On deployments configured with ALLOW_REGISTRATION=true \u2014 a supported and documented configuration \u2014 this means any internet user who can register. This issue has been patched in version 0.5.4."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-693",
              "description": "CWE-693: Protection Mechanism Failure",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-08T03:11:25.305Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/legeling/PromptHub/security/advisories/GHSA-9fhh-fjfg-5mr6"
        },
        {
          "name": "https://github.com/legeling/PromptHub/releases/tag/v0.5.4",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/legeling/PromptHub/releases/tag/v0.5.4"
        }
      ],
      "source": {
        "advisory": "GHSA-9fhh-fjfg-5mr6",
        "discovery": "UNKNOWN"
      },
      "title": "PromptHub: Authenticated SSRF via IPv6 filter bypass in `POST /api/skills/fetch-remote`"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-42261",
    "datePublished": "2026-05-08T03:11:25.305Z",
    "dateReserved": "2026-04-26T11:53:27.705Z",
    "dateUpdated": "2026-05-11T18:11:16.696Z",
    "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.

Detection rules are retrieved from Rulezet.

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.